Mechanical Properties Of Fluid

Viscosity refers to a fluid's resistance to flow. Glycerol, also known as glycerin or glycerine, has a higher viscosity compared to the other compounds listed. It is a thick, syrupy liquid with a relatively high molecular weight and strong intermolecular forces, which contribute to its higher viscosity.

Ethylene glycol (A) is also a viscous liquid, but its viscosity is generally lower than that of glycerol.

Methanol (B) and ethanol (D) have lower viscosities compared to both glycerol and ethylene glycol.

Therefore, the most viscous compound among the options provided is glycerol (C).