Which of the following is the main use of a semicolon?

to join Independent clauses that appear to be connected by a conjunctive adverb

to separate clauses, phrases, or series that might be confusing If commas alone were used

to separate items in a series of phrases that would ordinarily be separated be commas except that they already contain commas

to join Independent clauses closely related in thought

A. to join independent clauses that appear to be connected by a conjunctive adverb

Explanation:

A semicolon is the symbol "; " and it is used in a variety of situations:

- to separate a series/list that already includes commas

e. g. I travelled to Miami, Florida; Austin, Texas; and Los Angeles, California.

- to join independent clauses that are closely related in thought:

e. g. When I arrived, I thought I would have time to buy a snack; I didn't.

- and many more

However, the main usage of a semicolon is joining independent clauses that "appear to be connected by a conjunctive adverb":

e. g. She didn't study; thus, she failed the test.

The answer is A.