If the Correlation Between Two Variables Is 1, Then the Points

Multiple Choice

If the correlation between two variables is 1, then the points of their scatterplot:

A) all lie within 1 unit of the regression line.
B) all lie within $\frac{1}{2}$ unit of the regression line.
C) all lie on the regression line.
D) lie so that exactly half of the points are on each side of the regression line.