Answer:
c. compound
Explanation:
This is a compound sentence, you can easily get that by seeing that it contains a conjunction, but. Conjunctions include, for, and, nor, but, or, yet, so. You can remember it with the acronym, FANBOYS. Also, the sentence has two independent clauses, or two parts that could stand as a sentence by itself, opponents of labeling defend GMOs, proponents are skeptical.
