"John Buys More of Good X as His Income Increases

Multiple Choice

"John buys more of good X as his income increases, ceteris paribus," means

A) there is no cause-and-effect relationship between John's income and the quantity of good X he purchases if ceteris paribus applies
B) John's demand for good X depends exclusively on income
C) John's income and purchases of this good are being held constant
D) the change in John's income is the only factor being considered in explaining the change in his purchase of good X
E) the price of this good must have decreased in order for John to buy more of the good, regardless of changes in his income