When a body in equilibrium undergoes an infinitely small displacement, work imagined to be done, is known as A. Imaginary work B. Negative work C. Virtual work D. None of these

The correct answer is: C. Virtual work.

Virtual work is the work imagined to be done by a force when a body in equilibrium undergoes an infinitely small displacement. It is a concept in physics that is used to analyze the equilibrium of a system.

Imaginary work is not a real physical quantity. It is a mathematical concept that is used to simplify the analysis of a system.

Negative work is work that is done in the opposite direction of the force. It is a real physical quantity.

None of these is not a correct answer.