Answer:
A has Larger volume by 0.5cm^3
Density = Mass/ Volume
Volume = Mass / Density
So, for A,
Volume = 9/10 = 0.9cm^3
For B, Volume = 4/10 = 0.4cm^3
Therefore Volume of A is larger.
Alternatively, since density of both objects are same, the object with greater mass will have larger volume.