Answer : A)

Standard form of equation is

The vertex form of equation is

where (h,k) is the vertex
To find x coordinate of vertex we use formula

, a=1, b=-2 and c=-6
Plug in the values

Now plug in x=1 in the equation

h= 1 and k=-7
The vertex form of equation is

Plug in the values h=1 and k=-7
