Joe claims that the equation , where b is a real number, represents the graph of a straight line.

Which statement BEST classifies Joe's claim?
A.

Joe's claim is true only when b is 0.

B.

Joe's claim is true for all values of b.

C.

Joe's claim is not true for any value of b.

D.

Joe's claim is true only when b is not zero.

A. Joe's claim is true only when b is 0.