The Correlation Between a Family's Weekly Income and the Amount $r = 0.30$

Multiple Choice

The correlation between a family's weekly income and the amount they spend on restaurant meals
Is found to be $r = 0.30$
Which must be true?
I. Families tend to spend about 30% of their incomes in restaurants.
II. In general, the higher the income, the more the family spends in restaurants.
III. The line of best fit passes through 30% of the (income, restaurant$) data points.

A) II only
B) II and III only
C) I only
D) I, II, and III
E) III only