Injurious is defined as causing physical harm. With this in mind, the best piece of evidence to support this is 4.
Answer:
To express that the author's 'Muse' (or inspiration) is gone
Explanation:
"Where art thou, Muse, that thou forget'st so long
To speak of that which gives thee all thy might?
Spend'st thou thy fury on some worthless song,
Darkening thy power to lend base subjects light?"
I can sorta guess that this is asking something like "Where are you Muse, did you forget about me for so long?"
I believe it is a simple present sentence.
I would have to go with ( A) on that one
If you study over the course of a week, you have a better chance of remembering the material than if you study for a couple hours the night before and cram.