Katie buys several pairs of socks for $3 per pair. Which equation represents Katie's total cost, c, when she buys s pairs of socks and why? A)The equation c = 3s because the number of socks is multiplied by 3 to get the total cost.

B)The equation s = 3c because in order to get the number of socks purchased, the total cost is multiplied by 3.

C)The equation c = 3s + 1 because the number of socks is multiplied by 3 to get total cost, and then 1 is added to represent the first pair of socks.

D)The equation s= 3c + 1 because to get the number of socks purchased, the total cost is multiplied by 3, and then 1 is added to represent the first pair of socks.​