A linking verb doesn’t describe a direct action taken by subject, but links the subject to a predicate adjective or predicate noun. Therefore, your answer would be A.) The milk TURNED sour after sitting out on the counter overnight.
Words clause and brought have similar spelling: clause is spelled 'klawz', and brought is spelled 'brawt'. So, both are spelled with 'aw'. On the other hand, their meaning is different. Also, clause is a noun while brought is a verb. A clause is a syntactic construction that forms part of a sentence or is a whole simple sentence. Brought is simple past tense and past participle of 'bring'.
Allusions can provide deeper meaning in a literary work.