Read the sentence. since its establishment in 1961, the peace corps has countless people build better lives for themselves. which correctly identifies the italicized clause? elliptical clause noun clause adverb clause adjective clause

Assuming the italicized clause is Since its establishment, the correct answer here is elliptical clause.
Elliptical means that a word which would normally be part of a sentence is excluded, usually for stylistic reasons. Here, the verb is missing, which is why it is elliptical. The question is oddly formulated too - given that there is no verb here, it cannot be a clause, but rather a phrase, but since there is no such option here, then the correct answer is elliptical clause.

The correct answer is option a.

It has to be probably c