The incorrectly spelled word is:

☀ Diliver

The correct spelling is "Deliver." Deliver means to bring or transport something to a specific place or person.

The other options are spelled correctly:

• Denial: Refers to the act of refusing or rejecting something.
• Decision: Refers to the act of making a choice or coming to a conclusion.
• Deter: Means to discourage or prevent someone from doing something.