The number of atoms associated with a single body-centred cubic unit cell is

The number of atoms associated with a single body-centred cubic unit cell is 2

A sort of atom arrangement that can be found in nature is known as body-centered cubic (BCC). A body-centered cubic unit cell structure is made up of atoms organised in a cube with one atom in the centre and one atom at each of the cube's four corners.

Hence option B is correct