If the roots of the quadratic equation $a{x}^2+bx+c=0$ are imaginary, then for all real values of $x$, the minimum value of the expression $3a^2{x}^2+6abx+2b^2$ is

Assertion $\left(A\right): 3x^2-16x+4>-16$ is satisfied for some values of real $x$ in $\left(0,\frac{10}{3}\right)$. 

Reason $\left(R\right): a{x}^2+bx+c$ and $a$ will have the same sign for some values of $x\in R$ when $b^2-4ac>0$. 

The correct option among the following is