None other than D................wats the OA................

period & use are singular so "has and is" should be used in the sentence.

D is fine. when the subject is a clause, then its singular & so a singular verb is used

choice A --> OPsssssssss, sub-clause "what is much more difficult to determine" functions as predicative statement for the subjects in series, following each other (separated by commas) and joined with the plural form of verb "to be"

D is correct answer, look explanations below

gmatmachoman wrote:D is fine. when the subject is a clause, then its singular & so a singular verb is used

Could you please elaborate your comment plz...

thanks...!

btgyes wrote:

gmatmachoman wrote:D is fine. when the subject is a clause, then its singular & so a singular verb is used

Could you please elaborate your comment plz...

thanks...!

aha! subject clause --> singular, so we have subordinate and main clause/while subordinate clauses may take sing or plural verbs, the main clause cane take inly singular verb and we have here main clause answer is D accordingly

ruling source: MGMAT SC 2003 edition, page 24 top of the page

hi guys
to me only A has sence here, try to reverse the end of the sentence
the use to which......., the reason......., and meaning of .....are difficult to.....
we need plural working verb here
it kills C,D,E.
between A and B period has it kills B
so left with A

Two S+V agreement is: The period ... has been and what is to be determined ... is, D matches both.

.... what is much more difficult to determine are X, Y and Z
If I flip this clause,
X,Y and Z are much more difficult to determine.
So I think are is correct here.
Cannot get the logic

hi tetura84
unfortunately we are both wrong, correct version is D with is, i`ll try to say what Ron said about this sentence ( not exactly this but similar)
you can flip words after the working verb to estimate whether verb singular or plural only in cases when nothing before the verb can function as subject
in MG sentence correction page 42
Subject phrases or clauses are always singular, and in our case the role of subject clause plays
what is much more difficult to dermine-subject, singular is-working verb here always singular
so we can`t flip sentence here as we have legitimate subject-clause
another example they illustrate
whatever they want to do is (singular verb) fine
in OG10 page 686 #211 exists very similar senetnce and they also says is
ok i found needed link
https://www.manhattangmat.com/forums/pai ... t7994.html

@clock subject clause is the main clause it was not decided D - rather ruled from book /MGMAT strategic guide 2003 edition

clock60 wrote:hi tetura84
unfortunately we are both wrong, correct version is D with is, i`ll try to say what Ron said about this sentence ( not exactly this but similar)
you can flip words after the working verb to estimate whether verb singular or plural only in cases when nothing before the verb can function as subject
in MG sentence correction page 42
Subject phrases or clauses are always singular, and in our case the role of subject clause plays
what is much more difficult to dermine-subject, singular is-working verb here always singular
so we can`t flip sentence here as we have legitimate subject-clause
another example they illustrate
whatever they want to do is (singular verb) fine
in OG10 page 686 #211 exists very similar senetnce and they also says is
ok i found needed link
https://www.manhattangmat.com/forums/pai ... t7994.html