Hint: The smallest repeating array of atoms in a crystal is called a unit cell. A third common packing arrangement in metals, the body centered cubic unit cell has atoms at each of eight corners of a cube plus one atom in the center of the cube.
Complete step by step answer: -The number of close neighbors in a body centered cubic lattice of identical spheres is 8. In a body centered cubic lattice, spheres are present at 8 corners of the cube and the body centre. The sphere at the body centre is surrounded by eight spheres present at 8 corners. - Therefore,It has lattice points at the eight corners of the unit cell plus an additional point at the center of the cell. -It has unit cell vectors a=b=c and interaxial angles α+β+ϒ = 90˚. -The simplest crystal structures are those in which there is only a single atom at each lattice point. In the bcc structures the spheres fill 68% of the volume. -It is remarkable that for the bcc structure the next-nearest neighbours are only slightly further away which makes it possible for those to participate in bonds as well.
Hence, option D is correct.
Note: The bcc unit cell has a packing factor of 0.68. Some of the materials that have a bcc structure include lithium, sodium, potassium, chromium, barium, vanadium and tungsten. Metals which have a bcc structure are usually harder and less malleable than closely-packed metals such as gold.