Jenny is in charge of ordering t-shirts for the math club at her school. if she paid $252 for 21 t-shirts, which of the following statements is true? a. jenny paid $252 for 21 t-shirts, which is a rate of $21 per t-shirt. b. jenny paid $252 for 21 t-shirts, which is a rate of $231 per t-shirt. c. jenny paid $252 for 21 t-shirts, which is a rate of $33 per t-shirt. d. jenny paid $252 for 21 t-shirts, which is a rate of $12 per t-shirt.