Which letter is 5th to the right of the 3rd from the left end in the given arrangement?

To find the correct letter based on the given arrangement, let's break down the directions step-by-step.

First, we need to understand the reference points:
1. Start by finding the reference position from the left end, which is the 3^rd element from the left.
2. From that 3^rd position, move 5 places further to the right.

When combining positions in a linear sequence:
Moving right from a position measured from the left end means we add the two numbers together.
$\text{Final Position from Left}=3+5=8\text{th position from the left}$

Counting to the 8^th letter from the left end in the arrangement gives us the letter I.

Therefore, the correct option is I.