Which of the following indicates correct R (Gas constant) values in different units

a) $1.987calsmol{e}^{-1}{K}^{-1}$                         b) $8.314\times {10}^{7}Jmol{e}^{-1}{K}^{-1}$

c) $0.0821lit-atmmol{e}^{-1}{K}^{-1}$            d) $82.1lit.mol{e}^{-1}{K}^{-1}$