Maximum impact speed when shunting a single roller bearing fitted stock must be? A. 3 kmph B. 4 kmph C. 5 kmph D. 6 kmph

3 kmph
4 kmph
5 kmph
6 kmph

The correct answer is: A. 3 kmph.

The maximum impact speed when shunting a single roller bearing fitted stock must be 3 kmph. This is to ensure that the bearings are not damaged. If the impact speed is too high, the bearings can be damaged and may need to be replaced.

Option B is incorrect because it is too high. Option C is incorrect because it is too low. Option D is incorrect because it is not a valid option.