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").

[EX Q]: Thick feathers can be used for (A) climbing, cracking nuts and peeling fruit skins. (B) courtship and looking for food (C) killing prey, preening and feeding young (D) staying weatherproof, flexible and free of bacteria
[EX A]: D

[EX Q]: which of these formations are typically the highest point from sea level? (A) the sandy river bank (B) a long river channel (C) a cooled lava top (D) a lush green valley
[EX A]: C

[EX Q]: Unlike trees in the forest or a pond full of fish, metal is only available until (A) it is depleted for good (B) it is found on catfish scales (C) it becomes necessary to conduct electricity long distances (D) it is used to make diamond rings
[EX A]:
A