Which answer shows a correct order to solve this story problem?

maurine had to pay $2.52 tax on her purchases. she bought 3 books for $12.99 each, 2 pens for $0.69 each, and a magazine for $2.99. how much did maureen spend?

a.
step 1: add the price of a book and a pen.
step 2: multiply by 3 and then by 2.
step 3: add $2.99 to that result.
step 4: add the tax to the total of the purchases.

b.
step 1: calculate the total price of the 2 pens.
step 2: add $2.99 to that total.
step 3: calculate the total price of the 3 books.
step 4: add the tax to the price of the 3 books

c.
step 1: calculate the total price of the 3 books.
step 2: calculate the total price of the 2 pens.
step 3: add $2.99 to the total of the cost of the books and pens.
step 4: add the tax to the total of the purchases.

d.
step 1: add $2.99 to the amount of the tax.
step 2: calculate the total price of the 2 pens.
step 3: calculate the total price of the 3 books.
step 4: add the prices of the pens to the price of the books.