The set $\mathrm{A}=\left\{\mathrm{x}:\mathrm{x}\in \mathrm{R},{\mathrm{x}}^2=16\text{ and }2\mathrm{x}=6\right\}$ is equal to

• A

  $\varphi$

• B

  {14,3,4}

• C

  {3}

• D

  {4}