We are given a sequence $a_n = 2n + 3$. We are also given that $a_n = 17$. We need to find the value of $n$.

1. Problem Description

We are given a sequence $a_n = 2n + 3$. We are also given that $a_n = 17$. We need to find the value of $n$.

2. Solution Steps

We are given the sequence $a_n = 2n + 3$. We are given that $a_n = 17$.

So, we need to solve the equation $2n + 3 = 17$ for $n$.

Subtracting 3 from both sides of the equation, we get

$2n = 17 - 3$

$2n = 14$

Dividing both sides by 2, we get

$n = \frac{14}{2}$

$n = 7$

3. Final Answer

The value of $n$ is

7. Therefore, the answer is D.