Answer:
C. The awareness of impending death came about slowly, subtly
Explanation:
According to the given excerpt, the comment from Dickinson about expecting death in the line “since then — tis centuries — and yet/ feels shorter that the day/ I first surmised the horses head/ were toward eternity" is the awareness of impending death came about slowly, subtly.
This is because he slowly realizes as he feels shorter that day and finding out that the horses egad was toward eternity.
The answer is A and I'm just adding more characters to get to 20 total.
What is the writer attempting to persuade you of concerning the captivity of marine animals