The unit of force in C.G.S. system of units, is called A. Dyne B. Newton C. Kg D. All the above

The correct answer is A. Dyne.

A dyne is a unit of force in the centimeter–gram–second (CGS) system of units. It is defined as the force required to accelerate a mass of one gram at a rate of one centimeter per second squared.

A newton is a unit of force in the International System of Units (SI). It is defined as the force required to accelerate a mass of one kilogram at a rate of one meter per second squared.

A kilogram is a unit of mass in the SI system of units. It is defined as the mass of the International Prototype Kilogram (IPK), which is a cylinder of platinum-iridium alloy that is kept at the International Bureau of Weights and Measures (BIPM) in Sèvres, France.

Therefore, the unit of force in C.G.S. system of units is the dyne, not the newton or the kilogram.