There are 4 possibilities for cone or cup to hold your ice cream. There are 3 different sizes to choose from. There are 20 flavors of ace-cream, and then 15 choices of topping. Assuming you must choose 1 flavor of ice cream and 1 topping as the question implies, there are then 4*3*20*15 = 3600 different combinations to choose from. Answer is D: 3600
