Karla and 3 friends go to the movies and each person buys a ticket and a box of popcorn. Movie tickets cost $12 each. Together, Karla and her friends spend $68. Which equation can you use to find the cost of a box of popcorn? A. 4(12) + p = 68 B. 4(12 + p) = 68 C. 12 + 4p = 68 D. 12p + 4 = 68