The answer to the first analogy (mystery:clue :: eraser:) would be letter d. open. Mystery is to clue while eraser is to open. The answer to the second analogy (habit: custom :: extravagant: ) would be letter c. lavish.
The third one, read the directions carefully. The fourth one is for after you finish. The first and second are clearly incorrect.
A cougar runs faster then most animals but can only run for a short amount of time because it is taking up lots of energy to run that fast