prachich1987 wrote:Geologists once thought that the molten rock known as lava was an underground remnant of Earth's earliest days, sporadically erupting through volcanoes, but they now know that it is continuously created by the heat of the radioactivity deep inside the planet.

A) was an underground remnant of Earth's earliest days, sporadically erupting
B) had been an underground remnant of Earth's earliest days and sporadically erupted
C) was an underground remnant of Earth's earliest days, which sporadically erupted
D) would be an underground remnant of Earth's earliest days that sporadically erupted
E) was an underground remnant of Earth's earliest days, having sporadically erupted

OA : after some time

BastiG wrote:

prachich1987 wrote:Geologists once thought that the molten rock known as lava was an underground remnant of Earth's earliest days, sporadically erupting through volcanoes, but they now know that it is continuously created by the heat of the radioactivity deep inside the planet.

A) was an underground remnant of Earth's earliest days, sporadically erupting
B) had been an underground remnant of Earth's earliest days and sporadically erupted
C) was an underground remnant of Earth's earliest days, which sporadically erupted
D) would be an underground remnant of Earth's earliest days that sporadically erupted
E) was an underground remnant of Earth's earliest days, having sporadically erupted

OA : after some time

A: --> correct
B: wrong use of tense (past perfect)
C: which --> modifies word directly preceding
D: that --> same problem
E: wrong use of tense (having erupted)

bblast wrote:between a and c
i would pick c

a is wrong because of sporadically erupting. the action in continuous tense.

earnest10 wrote:

BastiG wrote:

prachich1987 wrote:Geologists once thought that the molten rock known as lava was an underground remnant of Earth's earliest days, sporadically erupting through volcanoes, but they now know that it is continuously created by the heat of the radioactivity deep inside the planet.

A) was an underground remnant of Earth's earliest days, sporadically erupting
B) had been an underground remnant of Earth's earliest days and sporadically erupted
C) was an underground remnant of Earth's earliest days, which sporadically erupted
D) would be an underground remnant of Earth's earliest days that sporadically erupted
E) was an underground remnant of Earth's earliest days, having sporadically erupted

OA : after some time

A: --> correct
B: wrong use of tense (past perfect)
C: which --> modifies word directly preceding
D: that --> same problem
E: wrong use of tense (having erupted)

The noun phrase "underground remnant of Earth's earliest days" is modified by which, this also correct the parallel error ... so I think 'C' is the answer .

BastiG wrote:

earnest10 wrote:

BastiG wrote:

prachich1987 wrote:Geologists once thought that the molten rock known as lava was an underground remnant of Earth's earliest days, sporadically erupting through volcanoes, but they now know that it is continuously created by the heat of the radioactivity deep inside the planet.

A) was an underground remnant of Earth's earliest days, sporadically erupting
B) had been an underground remnant of Earth's earliest days and sporadically erupted
C) was an underground remnant of Earth's earliest days, which sporadically erupted
D) would be an underground remnant of Earth's earliest days that sporadically erupted
E) was an underground remnant of Earth's earliest days, having sporadically erupted

OA : after some time

A: --> correct
B: wrong use of tense (past perfect)
C: which --> modifies word directly preceding
D: that --> same problem
E: wrong use of tense (having erupted)

The noun phrase "underground remnant of Earth's earliest days" is modified by which, this also correct the parallel error ... so I think 'C' is the answer .

But it is not 100% clear what is modified! which can refer to remnant but the word can also refer to days.