Explanation:

We are given four letters: $\text{K, T, C, Y}$. We need to find the odd one out based on a common characteristic shared by the other three. Let's analyze the visual structure of each letter: $\text{K}$ consists entirely of straight line segments. $\text{T}$ consists entirely of straight line segments. $\text{C}$ consists of a curved line segment. $\text{Y}$ consists entirely of straight line segments. Based on this observation, $\text{K, T, Y}$ are all formed using only straight lines, whereas $\text{C}$ is formed using a curved line. This makes $\text{C}$ the odd one out. Other properties like positional values (K=11, T=20, C=3, Y=25) or vowel/consonant status (all consonants) do not provide a clear distinction for a single odd one out.