Answer:
C. In a marriage, only one person has complete control.
Step-by-step explanation:
In the paragraph seven of the "A Bachelor's Complaint of the Behaviour of Married People", Charles call marriage a "monopoly, and not of the least invidious sort" because in a marriage, only one person has complete control according to him.
He says that the person with the upper hand in a marriage always try to keep his/her privilege exclusively adamant towards his/her partner. It is not a matter of one-sided/invidious sort of control but rather a natural way of how marriages work. The one with the exclusive privilege control the other person.