Concept:Leisure is free time; best used for productive personal development.Explanation:Leisure refers to time when one is not working or doing compulsory duties.It should be used for activities that refresh the mind and improve the person.Among the options, acquiring new skills is the most productive and meaningful use of leisure.House chores and extra classes are work or duty, not leisure.Attending church service is worship, not specifically leisure.Answer:C. acquire new skills