A Unitless physical quantity is A. Angle B. Latent heat C. Specify gravity D. Density

In geometry, an angle is a figure formed by two rays sharing a common endpoint, called the vertex of the angle. The minimum heat required to convert a solid into a liquid or vapour, or a liquid into a vapour, without change of temperature is called Latent Heat. Specific gravity is the ratio of the density of a substance to the density of a reference substance. As it is a ratio it doesn't have any units. Density is the ration between Mass and Volume.