Joan has a vegetable garden in her back yard that measures 8 1/2 ft by 7 1/2 ft which expression would not calculate the gardens perimeter?

a- 8 1/2 +7 1/2+8 1/2+7 1/2
b- 2. 7 1/2+2. 8 1/2
c- 2(8 1/2. 7 1/2)
d- 2 (8 1/2+7 1/2)​