There are a few acts of nature, such as a total solar eclipse or a

This one is copied from NYtimes :
https://www.nytimes.com/2013/06/08/nyreg ... .html?_r=0

Original::
There are a few acts of nature, such as the passage of Halley’s comet or the transit of Venus, that are so rare and so dramatic as to seem like metaphors for the virtues of patience itself. <<-- here virtues is plural -- I think that's a mistake in this sentence.


There are a few acts of nature, such as a total solar eclipse or a dormant volcano exploding, that are so rare and so dramatic as to seem like metaphors for the virtue of patience itself.

Splits are:
1) a dormant volcano exploding V/S an explosion of a dormant volcano
2) so rare and so dramatic as to V/S that are so rare and so dramatic that V/S that are so rare and dramatic enough that/as to
3) itself V/S themselves.

Lets take split-3 first : here itself is used to put emphasis on the virtue of patience. the virtue of patience is singular thus itself is fine. Thus, we can eliminate B ,D and E.

Between A and C: In C pronoun it is not appropriate as few acts of nature is a plural entity.

A) a dormant volcano exploding, that are so rare and so dramatic as to seem like metaphors for the virtue of patience itself
B) an explosion of a dormant volcano, that are so rare and dramatic enough that they seem like metaphors for the virtue of patience themselves
C) the explosion of a dormant volcano, that are so rare and so dramatic that it seems like a metaphor for the virtue of patience itself
D) the explosion of a dormant volcano, that are so rare and dramatic enough as to seem like a metaphor for the virtue of patience themselves
E) a dormant volcano exploding, that are so rare and so dramatic that they seem to be a metaphor for the virtue of patience themselves

Takeaway :
Itself and themselves can be used as reflexive pronoun or as noun intensifier. For more details refer page 233-234, MGMAT SC.
Check whether itself or themselves is following a verb or a noun, if it is following a verb then there are high chances that it is working as reflexive pronoun, or if it is following a noun then definitely it is used to put emphasis on the presence of that noun in the sentence and accordingly we will have to choose plural or singular form of reflexive pronoun.

Where we use reflexive pronoun : We use reflexive pronoun if action is done by subject on itself. e.g. He killed himself -- action done on self.

Incorrect usage: MR. XYZ will come for lunch with myself. << Incorrect. -- instead of myself use me.