Correct option is C
Given :
L E A P K X O Z A E Y W U D O A D S L Y R K E V U L
- Vowels: A, E, I, O, U
- Consonants: All other letters in the alphabet.
Condition : Consonants are immediately preceded and immediately followed by a vowel, and which consonant is repeated the most number of times in the series:
Logic: Vowel | Constant | Vowel'

From above there are 3 (Three) Consonants are immediately preceded and immediately followed by a vowel, and which consonant is repeated the most number of times in the series:
and most repeated consonant: L (appear 3 times)
Thus, the correct option is (c), L respectively