Concept: The question tests on basics of Rates(Time and Speed)

Solution:
 

Distance covered by the car in 2 hours = 55 * 2 = 110 km

The new speed after a reduction of 15 km/hr = 55 - 15 = 40 km/hr

T = D/S = 110/40 = 11/4 hours

Difference in time = (11/4) - 2 = 3/4 hours = 45 minutes

Option A