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: Constriction occurs when the muscular walls of blood vessels contract., Fact2: Cocaine also tightly squeezes, or constricts, the coronary arteries that feed blood to the heart., Question: What occurs when the muscular walls of blood vessels contract? (A) Dehydration (B) rapid expansion (C) smooth skin (D) smoking tobacco (E) loose bumping (F) pinched nerves (G) tight sqeezing (H) movement
G