What is the Greek letter for the answer "K"?

The Greek letter that corresponds to the answer "K" is Kappa. In the Greek alphabet, Kappa is the 10th letter and is represented by the symbol "Κ" in uppercase and "κ" in lowercase. The name "Kappa" itself phonetically starts with the 'K' sound, which aligns perfectly with its corresponding English letter.

Understanding the Greek alphabet is essential, especially in contexts such as mathematics, science, and Greek cultural references, where these symbols are frequently used. Other letters in the given choices represent different sounds and have distinct positions in the alphabet: Epsilon, for instance, is the 5th letter, Nu is the 13th, and Mu is the 12th. Thus, Kappa clearly stands out as the correct choice for the letter "K."