The missing character is N.
The first three characters are all vowels, and the last three characters are all consonants. The missing character is a consonant that comes between the vowels. The only consonant that comes between the vowels in the alphabet is N.
A. D is a consonant, but it does not come between the vowels in the alphabet. B. N is a consonant that comes between the vowels in the alphabet. C. P is a consonant, but it does not come between the vowels in the alphabet. D. T is a consonant, but it does not come between the vowels in the alphabet.
