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.
This is a reference to Biblical scripture. God said that HIs people (Christians) were as a city upon a hill. This means that we are an example of Christ before the whole world.
