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: Blood pressure is highest in arteries and lowest in veins., Fact2: What is Blood Pressure Blood pressure is the pressure on the blood vessel walls., Question: Where is force on the vessel walls highest? (A) arteries (B) feet (C) resistance (D) tibial vein (E) strong (F) capillaries (G) femoral vein (H) Summer
Output:
A