Which is the correct spelling?

Correct spelling is essential for clear written communication. Many English words, especially those derived from other languages, can be tricky to spell. The word in question refers to a set of questions used for surveys or studies.

• D. Questionnaire is the correct spelling. This word is derived from French and retains its original spelling with a double 'n' and 'aire' ending.
• A. Quest is incorrect; it is a different word meaning a search or pursuit.
• B. Questionaire is incorrect; this is a common misspelling, missing the second 'n'.
• C. Questionnar is incorrect; this is also a misspelling, missing the 'i' and having an incorrect ending.