The correct answer is C. 40 kmph.
A class ODC is a type of train that runs on broad gauge tracks. The speed of a train is determined by a number of factors, including the type of train, the weight of the train, the condition of the tracks, and the weather conditions. In general, A class ODC trains are designed to run at a speed of 40 kmph. However, the actual speed of a train may vary depending on the factors mentioned above.
Option A is incorrect because the speed of A class ODC trains is not 15 kmph. Option B is incorrect because the speed of A class ODC trains is not 25 kmph. Option D is incorrect because the speed of A class ODC trains is not “normal speed.” The term “normal speed” is not a specific speed and can vary depending on the type of train and the conditions of the tracks.