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: the Himalayas were formed by rock folding, Fact2: Folding and metamorphic rock Folding is caused by slow compression and the rock responds by bending., Question: What caused the Himalayas to form? (A) permineralization (B) Slow compression (C) Wind storms (D) a hydraulic system (E) objects that have mass (F) Dinosaurs (G) Glaciers (H) Water expanding
A:
B