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

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