MGMAT ques.

[madhur_ahuja]

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.

was an underground remnant of Earth's earliest days, sporadically erupting
had been an underground remnant of Earth's earliest days and sporadically erupted
was an underground remnant of Earth's earliest days, which sporadically erupted
would be an underground remnant of Earth's earliest days that sporadically erupted
was an underground remnant of Earth's earliest days, having sporadically erupted

[ketkoag]

A it is..
erupting....modifies the lava...

[hariharakarthi]

was an underground remnant of Earth's earliest days, sporadically erupting
A Correct.

had been an underground remnant of Earth's earliest days and sporadically erupted
Simple past is required here.

was an underground remnant of Earth's earliest days, which sporadically erupted
"Which sporadically erupted" incorrectly modifies "Earth's earliest days"

would be an underground remnant of Earth's earliest days that sporadically erupted
Conditional tense not required here. Morever, that sproadically erupted is not essential to the sentence here. Hence, wrong use of essential modifier.

was an underground remnant of Earth's earliest days, having sporadically erupted
Verb modfier "having .. erupted" does not modify the noun/subject or previous clause.

Hence A is correct.

Please correct if I have provided wrong explanation to any of ans choices.

[riteshbindal]

I may be wrong but thinking of C

[goelmohit2002]

was an underground remnant of Earth's earliest days, sporadically erupting
A Correct.

had been an underground remnant of Earth's earliest days and sporadically erupted
Simple past is required here.

was an underground remnant of Earth's earliest days, which sporadically erupted
"Which sporadically erupted" incorrectly modifies "Earth's earliest days"

would be an underground remnant of Earth's earliest days that sporadically erupted
Conditional tense not required here. Morever, that sproadically erupted is not essential to the sentence here. Hence, wrong use of essential modifier.

was an underground remnant of Earth's earliest days, having sporadically erupted
Verb modfier "having .. erupted" does not modify the noun/subject or previous clause.

Hence A is correct.

Please correct if I have provided wrong explanation to any of ans choices.

IMO E is wrong because having says that the eruption already happened....as having + simple past is used to show the relative past.....

Please tell me if I am wrong here....

[madhur_ahuja]

OA is A