The correct answer is A. 30 kmph.
TSL stands for Train Separation Lock. It is a safety system that is used to prevent collisions between trains. TSL is typically used on double-track sections of railway, where there are two tracks running in opposite directions.
When TSL is in operation, the first train that is dispatched after the system is introduced must travel at a speed of no more than 30 kmph. This is to allow time for the second train to be cleared from the section of track that the first train is approaching.
The other options are incorrect because they do not reflect the speed limit that is imposed by TSL. Option B, 25 kmph, is the speed limit that is typically used on single-track sections of railway. Option C, 15 kmph, is the speed limit that is typically used in areas with a high risk of derailment. Option D, normal speed, is not a specific speed limit.
In conclusion, the maximum speed of a train Ist train dispatched after introduced TSL on double line section is 30 kmph.