Answer:
C. grab the bull by the horns
Explanation:
Let's define all these idioms:
- "spill the beans": basically, this means to reveal the secret; here, there is no secret involved, so this is wrong.
- "have a short fuse": this essentially means that the person has a short temper and is easily angered; it doesn't talk about Troy's personality here, so this is wrong.
- "grab the bull by the horns": this means to get down to work and deal with a certain unpleasant situation; this is what the example illustrates because Troy mowed the lawn and pulled weeds until after dark, signifying that kind of bull-like determination. So, this is correct.
- "not one's cup of tea": basically, this means that something isn't to someone's liking; here, while we might be able to <em>infer</em> that, it's not explicitly illustrated, so this is wrong.
The answer is thus C.