When Two Variables in a Graph Are Related to a Third

Multiple Choice

When two variables in a graph are related to a third, changing the third causes

A) a movement along the curve.
B) no change in the curve because the third variable isn't on the axes.
C) a shift of the curve.
D) either a shift or a movement in the curve but more information is needed to determine which occurs.
E) None of the above answers is correct.