Write an expression for the n th term of the sequence $3,8,13,18,23,\dots$ Assume that n begins with 1.

A) $a_n=3+5n$
B) $a_n=3+6n$
C) $a_n=3+6(n+1)$
D) $a_n=3+5(n-1)$
E) $a_n=3+5(n+1)$

The common difference between every term in the sequence is 5, which means that to get from the first term (3) to any other term, we add 5 times the number of terms that have passed. However, we need to adjust for the fact that we start counting at 1 instead of 0. So, the nth term can be calculated as:

$$a_n=3+5(n-1)$$

This simplifies to:

$$a_n=5n-2$$

Therefore, the best choice for the expression of the nth term is D.