The relationship between speed, distance, and time is given by the formula: Distance = Speed × Time. Given the average speed of the bus is 60 km/h and the time of travel is 2.5 hours. Plugging these values into the formula, the distance covered = 60 km/h × 2.5 hours = 150 km. Option A (120 km) would be the distance for 2 hours. Options C and D are results of incorrect calculations.