The polynomial function f(x) is divided by x-k using synthetic division to produce q(x)=r/x-k which of the following must be true?
A. f(k)=r
B. f(r)=k
C. if r=0, then q(k)=0
D. if r=0, then the point (k,0) is on the graph of f(x)
E. the point (Krista) is on the graph of f(x).