a. B
b. D to E. She waited for 5 minutes
Step-by-step explanation:
a. The answer is B because her distance from the house reduced at point B. From A to B she was going away so the distance was increasing. But from B to C, she was going back since the distance was decreasing.
b. In the interval from D to E, her distance from the house didn't change (hence the horizontal line).
By reading the Time ax, at E 30 minutes passed by and at point D 25 minutes => 30 - 25 = 5 minutes.