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: 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

A: E
****
Q: Fact1: a breathing mask is used for keeping harmful particles from entering the respiratory system, Fact2: Oxygen enters the respiratory system through the mouth and the nose., Question: Breathing masks are used to keep harmful particles from entering the mouth and the what? (A) body (B) eyes (C) air (D) skin (E) gullet (F) nose (G) ears (H) lungs

A: F
****
Q: Fact1: Fungi lack chlorophyll, so they cannot make food by photosynthesis as plants can., Fact2: Mushrooms and molds are fungi., Question: what lacks chlorophyll? (A) green plants (B) moles (C) moles. (D) mold (E) apples (F) trees (G) moss (H) bushes

A:
D
****