Oh, what a delightful little sequence we have here! If we look closely, we can see that the letters are moving backwards through the alphabet. So, the next letter after R would be the letter Q. Just like painting a happy little tree, sometimes it's all about following the pattern and enjoying the process.
Assuming this is a word completion question in English and that only one letter is needed to complete the word, then the next letter is "Y". If there is no requirement that only one letter is needed to complete the word, then several letters can come next, including "I" and "O" to form the words "carrion" and "carrot". If, however, this is a question that asks to complete the pattern, then there are several possible answers. If the letters stand for numbers, specifically the order of the letter in the English alphabet, then the pattern is 3, 1, 18, 18. If the letters are simply abstract shapes, then the pattern is one curved line, three straight lines, one curved line with two straight lines, one curved line with two straight lines. Similarly, once can describe the letters by their symmetries. The letters could also represent their English sounds.
C
why would the letter I be the next letter in the sequence: C A R R
A
Y
The next letter in the sequence is S. The sequence follows the pattern of skipping every other letter in the alphabet, starting with C.
V
W
S
c
i
CRC CBO and COL
d