The answer is
[tex]13.33 gcm^{-3}[/tex]
The all the sides of the cube has same length.
If the length of one side of cube is 2 cm, the length of the width and height will also be 2 cm.
So,
[tex]Volume of cube = a^3[/tex]
as a = 2 cm
[tex]Volume = 8 cm^3[/tex]
[tex]Density = Mass/Volume[/tex]
[tex]Density = 80 g / 8 cm^3[/tex]
[tex]Density = 10 gcm^{-3}[/tex]
The density of the cube will be
[tex]10 gcm^{-3}[/tex]
The option is (A)