The word "kesahihan" is related to the concept of truth or accuracy. The correct answer, "kebenaran," directly translates to "truth" in English and aligns with the meaning of "kesahihan." The other options, such as "keberlakuan" (validity), "kesalahan" (mistake), "kematangan" (maturity), and "kemantapan" (stability), do not accurately reflect the meaning of "kesahihan." Therefore, the correct answer is "kebenaran."