Height gauge is for the safety of ________. A. Trolley B. Ohe C. Motor Trolley D. None of these

The correct answer is: A. Trolley.

A height gauge is a device used to measure the height of an object. It is typically used to ensure that objects are installed at the correct height, for safety reasons. For example, a height gauge may be used to ensure that a trolley is installed at the correct height, so that it does not collide with overhead obstacles.

The other options are incorrect because they are not objects that can be measured by a height gauge. An ohe is a type of overhead power line, and a motor trolley is a type of vehicle that travels on rails. Neither of these objects can be measured by a height gauge.