Answer:
A. (x+5)
Explanation:
We are given a quadratic expression
which we will factorize to see which of the given options is a binomial factor of it.
Finding the factors of 15 such that when added, they give a result of 8.
![x^2+3x+5x+15\\\\x(x+3)+5(x+3)\\\\(x+3)(x+5)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/5i25pgpjymcu98jut7uztzbzcwxd73wgyz.png)
Therefore, we can see that
is that binomial factor that is present in the given options so option A. (x+5) is the correct answer.