The given answer, "സൂറത്തുൽ ഫാത്തിഹ", is the correct answer because it is the first complete Surah (chapter) of the Quran. The other Surahs mentioned, Surah An-Nas, Surah Al-Ikhlas, and Surah Al-Feel, are also Surahs in the Quran, but they are not the first complete Surahs to be revealed.