The adsorption isotherm for a gas is given by the relation x = ap/(1 + bp) where x is moles of gas adsorbed
per gram of the adsorbent, p is the pressure of the gas, and a and b are constants. Then x
(A) increases with p
(B) remains unchanged with p
(C) decreases with p
(D) increases with p at low pressures and then remains the same at high pressure