Which statements among the following are correct?
$(i)$ Freundlich isotherm fails at high pressure of the gas.
$(ii)$ $\Delta H < 0$ for both physical and chemical adsorption.
$(iii)$ Physical adsorption is non-selective.
$(iv)$ Chemical adsorption is reversible,whereas physical adsorption is irreversible.

• A
  $(i), (ii), (iii) \& (iv)$
• B
  $(i), (ii) \& (iii)$ only
• C
  $(i), (iii) \& (iv)$ only
• D
  $(ii) \& (iv)$ only