At 320 K and 16 atm pressure, the molar volume of ammonia, NH3, is about 10% less than the molar volume of an ideal gas. The best explanation for actual volume being this much smaller than the ideal volume is that:
A) at this high temperature, a significant amount of NH3 decomposes to N2 and H2.
B) the intermolecular forces of attraction become significant at this temperature and this pressure.
C) the critical temperature and pressure of NH3 (405 K and 112 atm) are too close to the actual temperature and pressure of the NH3 above.
D) the volume occupied by the NH3 molecules themselves is significant at this high concentration.
E) ammonia is a real gas and not an ideal gas.