Question

Which sentence uses punctuation correctly?
A. The discovery, which was the first of its kind in several years, caused an international stir.
B. The discovery which was the first of its kind in several years, caused an international stir.
C. The discovery, which was the first of its kind in several years caused an international stir.
D. The discovery which was the first of its kind, in several years, caused an international stir.

Answer 1

The correct answer is C because it pauses after stating who did what.

Answer 2

I am certain that it is A as *which was the first of its kind in several years* is the subordinate clause and *the discovery caused an international stir is the main clause. :)