g x = x 2 + 55 What is the minimum value of the given function?

Choice B is correct. For a quadratic function defined by an equation of the form $g\left(x\right)=a{\left(x-h\right)}^2+k$, where $a$, $h$, and $k$ are constants and $a>0$, the minimum value of the function is $k$. In the given function, $a=1$, $h=0$, and $k=55$. Therefore, the minimum value of the given function is $55$.

Choice A is incorrect. This is the value of $x$ for which the given function reaches its minimum value, not the minimum value of the function.

Choice C is incorrect and may result from conceptual or calculation errors.

Choice D is incorrect and may result from conceptual or calculation errors.