The correct option(s) related to the Langmuir adsorption isotherm is(are):

(A) Langmuir adsorption isotherm assumes that adsorption sites are heterogeneous.
(B) The Langmuir adsorption isotherm suggests that adsorption occurs in a monolayer.
(C) At high pressure, the Langmuir adsorption isotherm predicts that the amount of adsorbed gas approaches a constant value.
(D) Langmuir adsorption isotherm applies to both physisorption and chemisorption equally.