For any real numbers $\alpha$ and $\beta$, let $y_{\alpha, \beta}(x), x \in \mathbb{R}$, be the solution of the differential equation
$
\frac{d y}{d x}+\alpha y=x e^{\beta x}, y(1)=1
$
Let $S=\left\{y_{\alpha, \beta}(x): \alpha, \beta \in \mathbb{R}\right\}$. Then which of the following functions belong(s) to the set $S$ ?