carbon-14 dating

[uptowngirl92]

The period when the great painted caves at Lascaux and Altamira were occupied by Upper Paleolithic people has been established by carbon-14 dating, but what is much more difficult to determine are the reason for their decoration, the use to which primitive people put the caves, and the meaning of the magnificently depicted animals.
(A) has been established by carbon-14 dating, but what is much more difficult to determine are
(B) has been established by carbon-14 dating, but what is much more difficult to determine is
(C) have been established by carbon-14 dating, but what is much more difficult to determine is
(D) have been established by carbon-14 dating, but what is much more difficult to determine are
(E) are established by carbon-14 dating, but that which is much more difficult to determine is


Guys I am seriously messed up with my singular/plural concepts:(
Ok,so I understood by the official explanation that since "period" is singular it requires "has"...agreed."What is much more difficult to determine " again is singular and therfore requires "is".Allright but while solving it I keep getting distracted by Lascaux and Altamira were occupied .. "and" and "were" are plural so while solving I keep choosing "have"..does'nt the plural parts have any thing to do here?

[amazonviper]

The period when the great painted caves at Lascaux and Altamira were occupied by Upper Paleolithic people has been established by carbon-14 dating, but what is much more difficult to determine are the reason for their decoration, the use to which primitive people put the caves, and the meaning of the magnificently depicted animals.
(A) has been established by carbon-14 dating, but what is much more difficult to determine are
(B) has been established by carbon-14 dating, but what is much more difficult to determine is
(C) have been established by carbon-14 dating, but what is much more difficult to determine is
(D) have been established by carbon-14 dating, but what is much more difficult to determine are
(E) are established by carbon-14 dating, but that which is much more difficult to determine is


Guys I am seriously messed up with my singular/plural concepts:(
Ok,so I understood by the official explanation that since "period" is singular it requires "has"...agreed."What is much more difficult to determine " again is singular and therfore requires "is".Allright but while solving it I keep getting distracted by Lascaux and Altamira were occupied .. "and" and "were" are plural so while solving I keep choosing "have"..does'nt the plural parts have any thing to do here?

This is a good question from the OG. The rule is that the subject and the verb should agree. Here the subject is the "period" and hence do not worry about the Lascaux and Altamira in the question.

Hope I cleared your question.

[viju9162]

Hi uptowngirl92,

Yes, they want us to get distracted . But as you mentioned, period is singular ...

for first part, read like this The period ( which is the subject) ------------------- has ( singular- verb for period).

for second part, read like this What is much more difficult ( which is the subject)--------- is ( verb)

[NandishSS]

The period when the great painted caves at Lascaux and Altamira were occupied by Upper Paleolithic people has been established by carbon-14 dating, but what is much more difficult to determine are the reason for their decoration, the use to which primitive people put the caves, and the meaning of the magnificently depicted animals.
(A) has been established by carbon-14 dating, but what is much more difficult to determine are
(B) has been established by carbon-14 dating, but what is much more difficult to determine is
(C) have been established by carbon-14 dating, but what is much more difficult to determine is
(D) have been established by carbon-14 dating, but what is much more difficult to determine are
(E) are established by carbon-14 dating, but that which is much more difficult to determine is

HI Guru,

I understand, here we have SV pair 'The period' is singular so eliminate C, D, E but could you pls help me to eliminate A determine is/are

Thanks And Regards
Nandish

[GMATGuruNY]

HI Guru,

I understand, here we have SV pair 'The period' is singular so eliminate C, D, E but could you pls help me to eliminate A determine is/are

Thanks And Regards
Nandish

A clause may serve as a NOUN.
More specifically, a clause may serve as a SUBJECT.
A clause serving as the subject of a verb is known as a SUBJECT CLAUSE.
A subject clause is ALWAYS SINGULAR.

OA: What is much more difficult to determine is the reason for their decoration, the use to which primitive people put the caves, and the meaning of the magnificently depicted animals.
Here, the portion in red is a SUBJECT CLAUSE in that it contains both a subject and a verb (what is) and serves as subject for the verb in blue (the second is).

A: What is much more difficult to determine are the reason for their decoration, the use to which primitive people put the caves, and the meaning of the magnificently depicted animals.
Here, are (plural) does not agree with what is much more difficult to determine (a subject clause, which by definition is considered singular).
Eliminate A.