I don't think that makes much difference. The two big problems are that the question didn't specify jets or props, and didn't specify how VX and VY were measured, i.e. as an EAS, IAS or TAS.
For a jet the EAS of VX is constant and that for VY decreases, the IAS of VX increases and VY decreases and the TAS of both increases. This is complicated by the fact that we often make the simplistic assumption in basic training that EAS and IAS are the same, for example in statements like 'the aircraft stalls at the same speed at 5000ft as it does in the circuit'. If this assumption is made then we get yet another answer.
A better question would have been:
Q. Which answer correctly completes the following statement?
For a jet aircraft, ignoring the effect of compressibility, the IAS of VX (1) and VY (2) with increasing pressure altitude.
A) (1) increases (2) decreases
B) (1) is constant (2) decreases
C) (1) is constant (2) is constant
D) (1) increases (2) increases
Bad wording is usually caused by translation errors. Once errors are spotted the questions are referred back to the JAA Subject Expert Teams (SETs) for remedial action.