Find out the osmotic pressure of $0.25\;M$ aqueous solution of area at $27^{\circ}$ (R=0.082) litre atm $k^{-1}\;mol^{-1}, R =1.987 cal\;k^{-1} mol ^{-1})$

Question

$\begin{array}{1 1} 0.615 \;atm \\ 61.5\;atm \\ 6.15\;atm \\ 0.0615\;atm \end{array}$