A car travels directly north on a straight highway at a constant speed of 80 \mathrm{~km} / \mathrm{hr} for a distance of 25 \mathrm{~km}. The car then continues directly north at a constant speed of 50 \mathrm{~km} / \mathrm{hr} for a distance of 75 more kilometers. The average speed of the car for the entire journey is closest to
Answer Choices
A. 55.2 \mathrm{~km} / \mathrm{hr}
B. 57.5 \mathrm{~km} / \mathrm{hr}
C. 65 \mathrm{~km} / \mathrm{hr}
D. 69.6 \mathrm{~km} / \mathrm{hr}
E. 72.5 \mathrm{~km} / \mathrm{hr}