If $x=c$  is a root of order 2 of a polynomial $f\left(x\right)\text{,}$ then $x=c$ is  also a root of the polynomial 

• A

  $f^{\mathrm{\prime }}\left(x\right)$

• B

  $f^{\prime \prime }\left(x\right)$

• C

  $f^{\prime \prime \mathrm{\prime }}\left(x\right)$

• D

  none of these