For one mole of a van der Waals gas, the compressibility factor `Z(=(PV)/(RT))` at a fixed volume will certainly decrease if [Given: "a", "b" are standard parameters for van der Waals gas]

Options

A. "b" increases and "a" decreases at constant temperature
B. "b" decreases and "a" increases at constant temperature
C. temperature increases at constant "a" and "b" values
D. "b" increases at constant "'a" and temperature