Detailed Instructions: 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").
Q: Fact1: Echinoderms lack a centralized nervous system., Fact2: Echinoderms are represented by the starfish., Question: What is something missing in starfish? (A) the body's largest organ (B) centralized nervous system (C) characteristics (D) layers of fat (E) permineralization (F) biological diversity (G) kinetic energy (H) A compound that donates proton
A:
B