Chemical Engineering - Fluid Mechanics - Discussion

Water hammer (or, more generally, fluid hammer) is a pressure surge or wave caused when a fluid (usually a liquid but sometimes also a gas) in motion is forced to stop or change direction suddenly (momentum change). Water hammer commonly occurs when a valve closes suddenly at an end of a pipeline system, and a pressure wave propagates in the pipe. It is also called hydraulic shock.

If valve is closed the flow of fluid will occurs rapids so most appropriate answer is B.

Water hammers occur when in a moving fluid the valve is closed all of a sudden due to which there is a heavy pressure increase. And according to this option[C] becomes the most apt option.