Answer:
Sample B and D
Step-by-step explanation:
The Density of an object is simply a characteristic property of the object and it depends absolutely on the mass of the object and the volume of object.
The density of an object will remain the same as long as the mass of the object does not change in relation to it's volume.
Helium gas has a molar mass of 4g/mol and will displace its own volume when placed in any sample.
Since sample B and D contains the same mass of helium gas, therefore, sample B and D contains the same volume of helium and this in turn implies that both samples will have the same density.