Matea spent $15.00 on protein bars and sports drinks. Each bar cost $3.00 and each sports drink cost $1.50. Which equation represents the number of protein bars, p, and the number of sports drinks, s, Matea could have bought?
A. p+s=15
B. p+s=4.50
C. 1.5p+3s=15
D. 3p+1.5s=15