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").

Ex Input:
Fact1: Ants communicate with chemicals called pheromones., Fact2: Ants communicate with the colony in the form of what is called pheremon trails., Question: Ants communicate with the colony using what? (A) Electrical energy (B) Chemical energy (C) visible energy (D) Decibels (E) pheremon traits (F) heat energy (G) refraction of light (H) mechanical waves

Ex Output:
E

Ex Input:
Fact1: when a metal rusts , that metal becomes orange on the surface, Fact2: Cast-iron and steel surfaces are susceptible to corrosion in the form of rust., Question: Cast-iron and steel surfaces are susceptible to becoming what on the surface? (A) hardness (B) solid (C) irritants (D) acids (E) orange (F) heat (G) Unsafe (H) damaging

Ex Output:
E

Ex Input:
Fact1: a cavern is formed by carbonic acid in groundwater seeping through rock and dissolving limestone, Fact2: When caves contain connecting rooms, they are called caverns., Question: What is one element used to create caves? (A) sunlight (B) heat energy (C) Calcium carbonate (D) hydrogen and oxygen (E) calcite (F) carbonic acid (G) less water (H) salinity

Ex Output:
F