Multiply & divide rational expressions: Error analysis

Rutendo tried to perform the following multiplication and reduce to lowest terms:

\frac{? 3 x + 15}{2 x + 16} ? \frac{x ? 7}{x^{2} ? 25}

This is his work:

Rewriting the first factor: $\frac{? 3 x + 15}{2 x + 16} = \frac{? 3 (x + 5)}{2 (x + 8)}$ ?

Rewriting the second factor: $\frac{x ? 7}{x^{2} ? 25} = \frac{x ? 7}{(x + 5) (x ? 5)}$ ?

Finding excluded values: $x \neq \pm 5$ ? and $x \neq ? 8$ ?

Multiplying and reducing to lowest terms:

$\begin{aligned} \frac{? 3 x + 15}{2 x + 16} ? \frac{x ? 7}{x^{2} ? 25} \\ = \frac{? 3 (x + 5)}{2 (x + 8)} ? \frac{x ? 7}{(x + 5) (x ? 5)} \\ = \frac{? 3 (x + 5) (x ? 7)}{2 (x + 8) (x + 5) (x ? 5)} \\ = \frac{? 3 (x ? 7)}{2 (x + 8) (x ? 5)} \end{aligned}$ ?

What mistake did Rutendo make?

(Choice A) ?
He excluded $x = ? 5$ ?, which doesn't make the final expression undefined.
(Choice B) ?
He didn't exclude $x = 7$ ?, which makes the numerator of the second factor equal to zero.
(Choice C) ?
He didn't rewrite the first factor correctly.
(Choice D) ?
He didn't rewrite the second factor correctly.

Precalculus

Course: Precalculus?>?Unit 4

Problem