The correct answer is B) A large valve that is routinely operated during plant operations. Large valves that are routinely operated during plant operations, such as in an industrial plant or facility, often require remote operation from a control station. This is because the physical size and weight of the valve makes it difficult or impractical to operate manually. By using an electric, pneumatic, or hydraulic motor to actuate the valve, the operator can safely and efficiently control the valve from a central location. The other answer choices are incorrect because: A) small valves routinely operated do not necessarily require remote operation, C) large valves rarely operated may not justify the cost of remote operation, and D) small valves rarely operated can typically be operated manually without the need for remote control.