Question: How to make frosting.

  Options: 
 A. In medium bowl, mix powdered sugar and water with spoon or electric mixer on low speed. Stir in vanilla and 1 tablespoon of the milk. Gradually beat in just enough remaining milk to make frosting smooth and spreadable. If frosting is too thick, beat in more milk, a few drops at a time.
 B. In medium bowl, mix powdered sugar and butter with spoon or electric mixer on low speed. Stir in vanilla and 1 tablespoon of the milk. Gradually beat in just enough remaining milk to make frosting smooth and spreadable. If frosting is too thick, beat in more milk, a few drops at a time.
Answer: B