Which one of the following is correctly spelled word?

dialogue

The correct answer is Option (4) → dialogue

The correctly spelled word is dialogue. The other words are misspelled.

• Diaphragm is a thin, muscular wall that separates the chest from the abdomen.
• Detoriate is spelled with two i's instead of one. The correct spelling is deteriorate.
• Discussion is spelled with two s's and one u. The correct spelling is discussion.