A-C refers to the first three letters of the English alphabet: A, B, and C. These letters are fundamental components of the English language, used in writing and communication. Each letter has its own distinct sound and can represent various words, making them essential for literacy and language development. In addition to their use in language, A-C are often utilized in grading systems, where A typically represents excellent performance, B indicates good performance, and C signifies average performance. This grading system is commonly found in educational institutions to assess student achievement.