Question

A comma

(A) cannot be used to correct most run-on sentences

(B) can be used to correct most run-on sentences

(C) can be used to combine two independent clauses correctly

(D) is required to combine two dependent clauses correctly

Answer 1

A comma might be used to combine two independent clauses correctly (option C). it is called a comma splice in a run-on sentence. Por example: "you can leave your study at any time, you only need to indicate your preference." 
It is very important to clarify that a run-on sentence is made up for two or more independent clauses connected improperly. 

Answer 2

Answer:

A. cannot be used to correct most run-on sentences

Explanation:

I just took the test and this answer was correct. I hope this helped you and good luck! :)