Patty's starting balance: $740.50
Add her paycheck deposit: + $325.00
Subtract her nonbank ATM withdrawal: - $75.00
Subtract her charitable donation check: - $25.00
Subtract her savings account transfer: - $100.00
Subtract the monthly checking fee: - $10.00
740.50 + 325.00 - 75.00 - 25.00 - 100.00 - 10.00 = $855.50
Therefore, Patty's checking account balance at the end of the month is $855.50, which is closest to answer choice B, $853.