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: Fertilization of gametes produces a diploid zygote., Fact2: Male gametes are sperm., Question: what produces a diploid zygote when fertilized? (A) bamboo (B) eggs (C) sperm (D) pollen (E) brain cells (F) lawns (G) embryos (H) h2o
A:
C