In this task, you are given two facts, and a multiple-choice question. Based on the given facts, answer the question with index of the correct option (e.g, "A").

Fact1: Most invertebrates have a nervous system., Fact2: Insects are the most common invertebrates., Question: what do most types of have nervous systems? (A) complex (B) animals (C) cows (D) insects (E) goats (F) protist (G) bacteria (H) sweat glands
D