Which sentence contains a correctly punctuated adjective phrase?

Question 1 options:

The discovery, which was the first of its kind in several years caused an international stir.

The discovery, which was the first of its kind in several years, caused an international stir.

The discovery which was the first of its kind, in several years, caused an international stir.

The discovery which was the first of its kind in several years, caused an international stir.