The correct answer is D. Casualty.
The correct spelling of the word is "casualty". It is a noun that means "a person who is killed or injured in a war or accident".
The other words in the list are spelled correctly.
- Utility: a thing that is useful or serves a purpose.
- Vitality: the quality of being full of life and energy.
- Speciality: a particular field of interest or expertise.
