Navinder
Isn't "a peace" incorrect ? I removed it from possible correct options because it stated "a peace" instead of "peace".
Dear
Navinder,
I'm happy to respond.

This is a subtle idiom, used in more sophisticated writing. Usually, the word "
peace" is used without an article, especially when it is used more generally. For example,
Caesar Augustus brought peace to the Roman Empire.
There, we are simply talking about the general quality of peace. By contrast, if we are talking about a specific period of peace and are discussing unique qualities of that period, then we use the idiom "a peace" to denote this very specific time.
Caesar Augustus brought to the Roman Empire a peace that the residents of the Italian peninsula enjoyed until barbarians attacked a few centuries later.
In that sentence, we are talking about a very specific historical time & place of peace: we idiomatically refer to this unique time as "
a peace." This is how the idiom is used in my SC question in this thread.
This is the kind of sophisticated structure that one sees only in high level reading. This is precisely why it's important to make a habit of doing sophisticated reading while preparing for the GMAT. See:
How to Improve Your GMAT Verbal ScoreDoes all this make sense?
Mike