If f is periodic, g is polynomial function, $f\left(g\left(x\right)\right)$ is periodic, $f\left(2\right)=3, \mathrm{and} g\left(4\right)=7, \mathrm{then} g\left(6\right)$ is

• A

  13

• B

  15

• C

  11

• D

  none of these