If the Vander Waal constant a is found to be zero for gas A, what are true ... ...

If the Vander Waal constant a is found to be zero for gas A, what are true regarding this gas?   I. Gas A does not behave ideally. II. Gas A behaves ideally. III. Gas A is Xenon.  
(A) I only
(B) ...
(C) ...
(D) ...
(E) ...

*This question is included in 06. Gases