Option-1: 200 km/h2

This option is incorrect. The provided answer suggests that the bus has an acceleration of 200 km/h2, but in the question, it is stated that the bus attains a speed of 20 km/h in 10 minutes. This means that the initial speed is 0 km/h (as it starts from a bus-stand) and it takes 10 minutes to reach a speed of 20 km/h. Therefore, the acceleration cannot be 200 km/h2.

Option-2: 120 km/h2

This is the correct answer. The bus attains a speed of 20 km/h in 10 minutes. To find the acceleration, we need to convert the time to seconds. 10 minutes is equal to 10 * 60 = 600 seconds. Then, we can use the formula: acceleration = (final velocity - initial velocity) / time. Substituting the values, we get: acceleration = (20 km/h - 0 km/h) / 600 s = 20 km/h / 600 s = (20/600) km/h/s = 1/30 km/h/s = 1/30 * (1000/3600) m/s2 =