Answer
Choice C
Work Step by Step
Using $(a+b)^2=a^2+2ab+b^2$ or the Square of a Binomial, the given expression, $
(x+7)^2
,$ is equivalent to
\begin{array}{l}
(x)^2+2(x)(7)+(7)^2
\\\\=
x^2+14x+49
\end{array}
Hence, the answer is $\text{
Choice C
.}$
