Definition: 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").
Input: Fact1: Differentiation is the process by which unspecialized cells become specialized., Fact2: How plant cells become specialized during development., Question: What is how plants become specialized during development? (A) dividing (B) trees and flowers (C) differentiation (D) unicellular organisms (E) pollenating (F) melanin content (G) some prokaryotes (H) Extensive bone growth
Output:
C