O Which of the following illustrates the law of demand? O a. Chen buys more ice cream at $4 per half-gallon than at $3 per half gallon, ceteris paribus. O b. Jim buys more books at $15 each than at $12 each, ceteris paribus. O O c. Karissa buys fewer sweaters at $50 each than at $75 each, ceteris paribus. O d. Jorge buys fewer pencils at $2 per pencil than at $1 per pencil, ceteris paribus. O O O