Concept:The word "Maintainence" is misspelt; its correct form is "Maintenance".
Explanation:The word "Maintainence" is incorrectly spelled.
The correct spelling is "Maintenance".
It means keeping something in good condition.
Example: This house needs a lot of maintenance.
The other options are correctly spelled:
Countenance means a person's face or expression.
Assistance means help or support.
Perseverance means persistence despite difficulty.
Thus, the incorrect word is in option A.
Answer:A. Maintainence