Which letter corresponds to the answer "O"?

The answer "O" corresponds to the letter Omicron, which is the 15th letter of the Greek alphabet. In the Greek numeral system, Omicron also represents the number 70, and its pronunciation is akin to the English "o." Understanding the origins and use of different letters in various contexts, such as the Greek alphabet, can clarify this correspondence.

Sigma, Rho, and Alpha are also letters from the Greek alphabet but do not represent the sound or the letter "O." Sigma correlates with the "S" sound, Rho with the "R" sound, and Alpha is associated with the "A" sound, making them distinctly different from Omicron in both pronunciation and representation. This highlights the specific link between the letter and its corresponding representation.