A student is registered for a four$-$year degree. She has a fund of R$40000$ available to cover expenses over the next four years. She withdraws the same amount from the fund at the beginning of each month. If the interest rate is $7,5\%$ per year, compounded monthly, then the value of each monthly withdrawal isa.R$967,16.$b$.$R$961,15.$c$.$R$712,70.$d$.$R$833,33.$