Number of letters skipped in between adjacent letters in the series decreases by one. Which of the following series is observing the rule?

If it is possible to make a meaningful word with the second,the fifth,the tenth,and the twelfth letters of the word $METROPOLITAN$,which of the following will be the third letter of that word? If no such word can be made,give $X$ as the answer,and if more than one such word can be made,give $M$ as the answer.

Find which one word cannot be made from the letters of the given word: $REPRIMAND$.

Arrange the given words in alphabetical order and choose the one that comes in the middle.

If each vowel of the word $WEBPAGE$ is substituted with the next letter of the English alphabet,and each consonant is substituted with the letter preceding it,which of the following letters will appear thrice?

If the positions of the first and the sixth letters in the word $DISTRIBUTE$ are interchanged; similarly the positions of the second and the seventh,the third and the eighth and so on,which of the following letters will be the fifth from left after interchanging the positions?