If the second, fourth, sixth, and eighth letters (from the left end) of the word “RECONSIDER” are combined to form a single meaningful English word (using each letter only once) starting with a vowel, what will be the third letter from the left end of the word formed? If more than one such word can be formed, mark the answer as X, and if no such word can be formed, mark the answer as Y.

The correct option is E.

Step 1: Identify the specified letters from the word "RECONSIDER"
Let Puff out the letters of the word RECONSIDER according to their positions from the left end:
- 1st letter: R
- 2nd letter: E
- 3rd letter: C
- 4th letter: O
- 5th letter: N
- 6th letter: S
- 7th letter: I
- 8th letter: D
- 9th letter: E
- 10th letter: R

The 2nd, 4th, 6th, and 8th letters are E, O, S, and D respectively.

Step 2: Form a meaningful word starting with a vowel
The vowels present in the set {E, O, S, D} are E and O.
Using each of the four letters (E, O, S, D) exactly once to form a word starting with a vowel, we get the word: ODES.

Step 3: Determine the third letter from the left end
In the word ODES:
- 1st letter: O
- 2nd letter: D
- 3rd letter: E
- 4th letter: S

The third letter from the left end of the formed word is E.