Sentence Correction

We who graduated from high school in the Unites States in the early '60s were caught in the middle of the crisis in education created by the Soviet Union's "Sputnik" success.

A. We who graduated from high school in the United States in the early '60s were
B. We, who graduated from high school in the United States in the early '60s, were
C. We who then graduated high school in the United States in the early '60s were
D. Those of us who then graduated from high school in the United States in the early '60s were
E. We high school graduates who were in the United States in the early '60s were

I am reposting this question as I am not convinced with the answers to the old post. I do not know the OA. I think it should be B

I shall be glad if an expert replies to this post.

Thanks!