`NH_(3)` gas is liquefied more easily than `N_(2)`. Hence
A. van der Waals constant `a` and `b` of `NH_(3)gt` that of `N_(2)`
B. van der Waals constant `a` and `b` of `NH_(3)lt` that of `N_(2)`
C. `a(NH_(3))gta(N_(2))` but `b(NH_(3))ltb(N_(2))`
D. `a(NH_(3))lta(N_(2))` but `b(NH_(3))gtb(N_(2))`