MrGatlin Went into a Supermarket Where He Saw a New

Mr.Gatlin went into a supermarket where he saw a new kind of toothpaste on a shelf,ticketed at $2.69.He decided to try it,so he took it to the checkout and placed it on the moving counter.The staff member at the checkout ran up the sale,took Mr.Gatlin's money and put the toothpaste in a bag,handing it with the receipt and the change to Mr.Gatlin.A contract was formed when:

A) Mr.Gatlin picked up the toothpaste.
B) Mr.Gatlin put the toothpaste on the checkout counter.
C) Mr.Gatlin paid for the toothpaste.
D) The supermarket employee rang in the sale and took his money.
E) The supermarket employee gave Mr.Gatlin the bag,the receipt and his change.