You will be given a trivia clue, and the category it belongs to. You should answer with the best answer that belongs in the category and is described by the clue. For simplicity, answers should be in all lower cased letters.

[EX Q]: Category: THE HECUBA, YOU SAY 
Clue: Hecuba lays a guilt trip on this eldest son for going into his final combat
[EX A]: hector

[EX Q]: Category: "E" BAY 
Clue: Thinking green, biologist Ernst Haeckel coined this term for the way animals interact with the environment
[EX A]: ecology

[EX Q]: Category: FUN IN THE SNOW 
Clue: According to Newton's Third Law of Motion, every action has an equal and opposite one of these.
[EX A]:
reaction