If A and B any two sets, then ${(\mathrm{A}\cap \mathrm{B})}^{\text{'}}$ is equal to

• A

  ${\mathrm{A}}^{\text{'}}\cap {\mathrm{B}}^{\text{'}}$

• B

  ${\mathrm{A}}^{\text{'}}\cup {\mathrm{B}}^{\text{'}}$

• C

  $\mathrm{A}\cap \mathrm{B}$

• D

  $\mathrm{A}\cup \mathrm{B}$