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:
An echo is produced by what type of reflection of sound source? (A) Direct (B) Distant (C) Varied (D) Single
answer:
D


question:
Cellular respiration releases (A) blood (B) waste (C) snot (D) feces
answer:
B


question:
After a storm, a glass vial with markings on it can tell (A) how loud a baby is (B) how wet an area got (C) how sad a puppy is (D) how bad a skunk smells
answer:

B