The correct answer is D. 64th.
The series is 5, 8, 11, 14, …, 320. The common difference is 3. To find the nth term of the series, we can use the formula $a_n = a_1 + d(n-1)$, where $a_n$ is the nth term, $a_1$ is the first term, $d$ is the common difference, and $n$ is the number of terms.
In this case, $a_1 = 5$ and $d = 3$. We want to find the value of $n$ such that $a_n = 320$. Substituting these values into the formula, we get $320 = 5 + 3(n-1)$. Solving for $n$, we get $n = 64$. Therefore, the 64th term of the series is 320.
Option A is incorrect because 104 is not a term of the series. Option B is incorrect because 105 is not a term of the series. Option C is incorrect because 106 is not a term of the series.