Answer: C.240 mi
Explanation:
In the given picture, Let ABC be the bigger triangle and BDC be the smaller triangle.
Then, In ΔABC and ΔBDC
∠C=∠C
∠D=∠B =90°
Therefore, ΔABC ≈ ΔBDC [By AA similarity rule]
We know that the sides of similar triangles are proportional, then

Hence, The length of new road = 240 mi