A) The poem that I read in class is by Maya Angelou
Explanation:
A subordinate clause is a clause that does not express a complete thought. As such, it cannot stand on its own. These clauses do have a subject and a predicate, but are dependent on the other words to form a complete sentence.
In this particular case, the only sentence that is subordinate is "The poem that I read in class is by Maya Angelou". It does have a subject and a predicate, but does not share a complete thought. An example of a complete sentence would be: The poem that I read in class is by Maya Angelou is quite interesting.