Concept: Sihahus-Sitta refers to the six authentic Hadith collections.Explanation:The six authors of Sihahus-Sitta are:• Muhammad b. Isma'il al-Bukhari• Muslim b. al-Hajjaj• Abu Dawud• at-Tirmidhi• an-Nasa'i• Ibn MajahMalik b. Anas authored al-Muwatta, which is not part of the six books.Therefore, he is the exception among the listed names.Answer: D. Malik b. Anas