The tendency of a liquid drop to contract and occupy minimum area is due to

The correct answer is B because of the phenomenon of surface tension. Surface tension is the property of a liquid surface that causes it to behave like a stretched elastic membrane. This occurs because molecules in the interior of the liquid are pulled equally in all directions by intermolecular forces, whereas molecules at the surface experience a net inward pull. To achieve a state of stability and minimum energy, the liquid tries to minimize its surface area. Since a sphere has the smallest surface area for a given volume, liquid drops naturally contract into a spherical shape. Viscosity relates to internal friction, density to mass per unit volume, and vapour pressure to evaporation, none of which primarily drive the contraction of a drop.