Sentence Correction

The widely accepted big bang theory holds that the
universe began in an explosive instant ten to twenty
billion years ago and has been expanding ever since.
(A) that the universe began in an explosive instant
ten to twenty billion years ago and has been
expanding
(B) that the universe had begun in an explosive
instant ten to twenty billion years ago and had
been expanding
(C) that the beginning of the universe was an
explosive instant ten to twenty billion years ago
that has expanded
(D) the beginning of the universe to have been an
explosive instant ten to twenty billion years ago
that is expanding
(E) the universe to have begun in an explosive
instant ten to twenty billion years ago and has
been expanding

A

I agree that this is the best of the choices given, but here is my question:

The theory holds two things -- that it began....and that it has been expanding.... I'm not clear how omitting the second that is OK.

This is logical continuation from previous event and not parellelism.
Note that tense itself differs from past tense to present perfect tense. Also "that" introduces a new clause with universe as subject.

The theory holds two things -- that it began....and that it has been expanding.... I'm not clear how omitting the second that is OK.

Here the second that makes theory as subject instead of Universe. The correct version should be Universe is expanding not the theory.

kris610 wrote: The theory holds two things -- that it began....and that it has been expanding.... I'm not clear how omitting the second that is OK.

I think you might be confusing between the two usages of that as a Demonstrative pronoun and as a conjunction.

If in this question, we had: ...and that has been expanding ever since.., the usage of that would be as a Demonstrative pronoun and it would not be very clear what that refers to.

On the other hand, if there was a clause after and, the usage of that would have made more sense (since in that case, that would have been used as a conjunction).

The widely accepted big bang theory holds that the universe began in an explosive instant ten to twenty billion years ago and that it has been expanding ever since.