You use the semicolon with an independent clause when you join two of the independent clauses in a sentence without using a conjunction. So basically the semicolon replaces the conjunction when you're combining two independent clauses.
Answer: D) Excited and relieved.
Explanation: The tone of a text or sentence is the author's or speaker's attitude towards the audience, the subject or even the characters of the text. There are many different kinds of tones, like: positive, negative, objective, sad, angry, etc. In the given passage from "Frankenstein" by Mary Shelley we can see that the overall tone is excited and relieved, we can clearly see this in the phrase " but when I became assured that my enemy had indeed fled, I clapped my hands for joy, and ran down to Clerval."
It provides others perspectives on the topic
Are you asking how to punctuate the sentence? If so, then....
The squirrel reached for the bird feeder, for he saw an abundance of sunflower seeds.
A comma is needed before the coordinating conjunction 'for' that separates the two independent clauses.