instruction:
In this task, you are given a multiple-choice question and you have to pick the correct option. Answer with option indexes (i.e., "A", "B", "C", and "D").
question:
The sidewalk next to a house having a crack in it and having vegetation growing from it is considered? (A) insects (B) weathering (C) erosion (D) lava
answer:
B


question:
Which of these objects could combust (A) Seashells (B) Grass (C) A cat (D) A paint can
answer:
D


question:
What is a source of oxygen through photosynthesis? (A) lakes (B) car engines (C) sunflowers (D) people
answer:

C