Answer
Answer choice $B$: $3 + (n-1)(5)$
Work Step by Step
The common difference between each term is $5$. The first term is $3$.
$a + (n-1)d$,
This is the formula for finding a function rule, $a$ is the first term and $d$ is the common difference. Plug these values in.
$\boxed{3 + (n-1)(5)}$
The answer is $\boxed{B}$