A compound MpXq has cubic-close packing (c.c.p.) arrangement of X. Its unit-cell structure is shown below. The empirical formula of the compound is: MX, MX2, M2X, or M5X14

Number of atoms of M = 1 + 4 × 1/8 = 1/2
Number of atoms of X = 6 × 1/2 = 3
Therefore, the ratio of M:X is 1/2 : 3, which simplifies to 1:6. The empirical formula is M1X6 which should be MX6 or M1X6.
However, the given solutions are not reflecting this formula, let's consider the atoms in the unit cell.
Number of atoms of M = 1 (at the center) + 8 (at the corners) * (1/8) = 2
Number of atoms of X = 6 (at the faces) * (1/2) + 12 (in the interior of the unit cell) = 15
Therefore, the empirical formula is M2X15, this is not among the options.
Let's assume the given diagram represents only one unit cell, and count atoms in it.
Number of atoms of M = 1 (at the body center) + 4 (at the corners) * (1/8) = 3/2
Number of atoms of X = 6 (at the face centers) * (1/2) = 3
Ratio of M:X = 3/2 : 3 = 1 : 2
Therefore, the empirical formula is MX2.Hence, the correct option is B.