The word "carousel" (meaning a merry-go-round) follows specific English spelling rules.
Carousel (Correct): This is the standard spelling. It originates from the French word carrousel and the Italian carosello, but in modern English, it is spelled with one 'r' and one 'l'.
Carousell: Incorrect; it adds an unnecessary second 'l' at the end.
Carrousel: This is the French spelling. While sometimes seen in older texts, it is not the standard spelling for modern English competitive exams.
Karusel: Incorrect; it uses a 'k' instead of a 'c', which does not fit the Latin/Romance origin of the word.