The entire first period class agreed that yesterday’s algebra homework which the teacher assigned was a really fun challenge. how should the writer revise the punctuation in the sentence so that it is grammatically correct?

The answer to your question would be that the writer should revise the punctuation in the sentence for it to be grammatically correct in the following way: The entire first period class agreed that yesterday's algebra homework, which the teacher assigned, was a really fun challenge.

The information introduced by the relative clause "which the teacher assigned" should be offset with commas because it is nonessential. If it was dropped, the meaning of the sentence would not be altered (a)

a) The entire first period class agreed that yesterday's algebra homework was a really fun challenge.