Read the Following Paragraph and Answer the Question below (1) Though people make appointments and schedule events, life often gets in the way. (2) Despite one's best intentions, one often finds that one must reschedule or cancel even the most important engagements. (3) This frequently happens to me when my coworker and close personal friend schedule a mid-afternoon coffee break with me. (4) Although the two of us want to break for coffee, we're too busy to stop working.

Which sentence should be revised to ensure that a subject and verb agree in number?

A. Sentence 1

B. Sentence 2

C. Sentence 3

D. Sentence 4

I would like a detailed explanation of this problem if possible since I am terrible at English Grammar.