The minister was punished with defection for his anti-party activities.

Answer: Option D

Defection : the desertion of one's country or cause in favour of an opposing one.
Resignation : an act of resigning from a job or office.
Co-operation : the action or process of working together to the same end.
Invitation : a written or verbal request inviting someone to go somewhere or to do something.
Joining : link; connect.

Antonym of Defection is Joining