Which one of the following characteristics is associated with adsorption?

(a) $∆$G, $∆$H and $∆$S all are negative

(b) $∆$G and $∆$H are negative but $∆$S is positive

(c) $∆$G and $∆$S are negative but $∆$H is positive

(d) $∆$G is negative but $∆$H and $∆$S are positive