I would say A " As I look back now on my life" shows the characters reflection of themselves and the people around them.
The correct answer is
C. The baseball player hit the ball, and the crowd cheered.
A and B would create grammatically incorrect sentences, while we can see an oxford comma in the last one.
To show that a specific person is speaking out loud. Quotations should be in dialogue, any speech and can be used in movie/book titles.
He vows to forgive Gertrude for what she has done in marrying Claudius. He vows to apologize to Ophelia for the way he has treated her.
