Verified Answer :

Answer:  The correct option is (D) (-2, -7).

Step-by-step explanation:  We are given to identify the vertex for the graph of the following function :

\(y=3x^2+12x+5~~~~~~~~~~~~~~~~~~~~~~~~~~~(i)\)

We know that

the vertex of the graph of the function \(y=a f(x-h)+k\) is given by \((h,k).\)

From equation (i), we have

\(y=3x^2+12x+5\\\\\Rightarrow y=3(x^2+4x)+5\\\\\Rightarrow y=3(x^2+4x+4)+5-12\\\\\Rightarrow y=3(x+2)^2-7\\\\\Rightarrow y=3\{x-(-2)\}^2+(-7).\)

Therefore, the vertex of the graph of function (i) will be

\((h,k)=(-2,-7).\)

Thus, (D) is the correct option.