Adsorption is accompanied with

a. decrease in entropy of system

b. decrease in enthalpy

c. the value of $\mathrm{T}∆\mathrm{S}$ is negative

Adsorption is the accumulation of molecular species at the surface rather than in the bulk of a solid or liquid. As accumulation of molecular species on the surface of bulk, this leads to decrease in entropy. Enthalpy of physisorption is low whereas enthalpy of chemisorption is high.

Adsorption reduces entropy, therefore $\mathrm{T}∆\mathrm{S}$ is negative. 

Hence the correct option is (D).