Plz

at a sporting goods store, sweatshirts are on sale for 30% off the regular price, r, in dollars. lana has a coupon for $5 off any single item at the store. the expression 3(r – 0.3r) – 5 represents the total cost before tax if lana buys 3 sweatshirts.
a. 3r-0.3r-5
b. 2.1r-15
c. 3(0.7r)-5
d. 3(r-0.3r-5)
e. 3r-0.9r-5

which ones show whether or not it represents the total cost before tax.