Which situation has a sum of zero?

A. Borrowing $20 from my brother and paying him back $10.

B. Earning $5 for mowing the lawn and spending $5 on candy.

C. Earning $10 for mowing the lawn and spending $2 on candy.

D. Borrowing $10 from my mom and then another $5 from her the next day.

O B
O C
O A
O D