His wife enjoined him to change his ways.

• Option A, asked, is too weak. A simple request would not be enough to get someone to change their ways.
• Option B, pleaded, is more forceful than asked, but it still does not convey the same level of urgency as enjoin.
• Option D, threatened, is too strong. A threat would only make the situation worse.

Therefore, the correct answer is C. urged.