An ideal gas expands from $10^{-3} m^3$ to $10^{-2} m^3$ at 300 K, against a constant pressure of $10^5 N m^{-2}$. The work done on it is

Question

(a) -0.9 kJ
(b) -900 kJ
(c) 270 kJ
(d) -270 kJ