The answer here would be C. ON/C 6 8 – 5 – 6 2 . 5 0 + 7 5 =
Following her keypresses, she has to turn the calculator on by pressing "ON/C". Entering her current balance, she presses 6 then 8, subtracting her 2 checks by entering "-" then 5, and again for 62.50. Lastly, she adds the amount deposited which is 75. Pressing the "=" sign then tells her how much her new balance is.