Select the correct alternative from the given choices.
For non empty sets $\mathrm{A}$ and $\mathrm{B}$, which of the following is a non empty set?
(A) $\mathrm{A}-\mathrm{A}^{\mathrm{c}}$
(B) $(\mathrm{A}-\mathrm{B}) \cap(\mathrm{A} \cap \mathrm{B})$
(C) $\mu-\left(\mathrm{A} \cup \mathrm{A}^{c}\right)$
(D) $\mathrm{A} \cap \mathrm{A}^{\mathrm{c}}$