Please can you help me solve this question :

The president of the Southern University wants to forecast student enrolments for this academic year based on the following historical data: (5 years ago enrolment was 14642), (4 years ago enrolment was 15578), (3 years ago enrolment was 16179 ), (2 years ago enrolment was 17156 ) and in the last year enrolment was 20810. What is the forecast for this year using three periods simple moving average? O a. 15466.333 O b. 18048.334 O c. 16304.333 O d. 16873