Ann opened a savings account with an initial deposit of $250. Which combination will result in a zero balance in Ann's account?
A deposit $20 in the first week and withdraw $270 in the second week
B deposit $270 in the first week and withdraw $20 in the second week
C deposit $20 in the first week and withdraw $250 in the second week
D deposit $250 in the first week and withdraw $20 in the second week