ANS:A - viscosity

Poise is the unit of viscosity. Viscosity is a measure of a fluid's resistance to deformation or flow. It determines how easily a fluid flows in response to an applied force or shear stress. The poise (symbol: P) is the unit of dynamic viscosity in the centimeter-gram-second (CGS) system of units. In the International System of Units (SI), viscosity is typically measured in pascal-seconds (Pa·s) or millipascal-seconds (mPa·s). However, in the CGS system, the poise is the primary unit of viscosity, with the millipascal-second being the corresponding SI unit. Therefore, the poise is indeed the unit of viscosity.