Which of the following contain same number of entities?

The entities contain by each options,

(A) $1\times 21\times {\mathrm{N}}_{\mathrm{A}}$ (B) $3.5\times 6\times {\mathrm{N}}_{\mathrm{A}}$

(C) $2\times 7\times {\mathrm{N}}_{\mathrm{A}}$   (D) $2.1\times 10\times {\mathrm{N}}_{\mathrm{A}}$

Thus, the option which have same entities are.

(A) Number atoms in 1 mole ${\mathrm{CuSO}}_4\cdot 5{\mathrm{H}}_2\mathrm{O}$

(B) Number of neutrons in 3.5 mole of${\mathrm{CH}}_4$