Which shows a correct way to solve this problem?

sheri bought 3 books and a magazine at the bookstore. each book cost $9 and the magazine cost $2.

how much did sheri spend at the bookstore?

a.

step 1: multiply 9 × 3.
step 2: add 2 to the product.

b.

step 1: multiply 9 × 2.
step 2: add 3 to the product.

c.

step 1: add 9 + 3.
step 2: multiply the sum by 2.

d.

step 1: add 9 + 2.
step 2: multiply the sum by 3.