Marianne is a professional chess player who hums audibly while playing

Marianne is a professional chess player who hums audibly while playing her matches, thereby distracting her opponents. When ordered by chess officials to cease humming or else be disqualified from professional chess, Marianne protested the order. She argued that since she was unaware of her humming, her humming was involuntary and that therefore she should not be held responsible for it.

Which one of the following, if true, most undermines Marianne’s argument against the order?

(A) The officials of chess have little or no authority to control the behavior of its professional players outside of matches.
(B) Many of the customs of amateur chess matches are not observed by professional chess players.
(C) Not all of a person’s involuntary actions are actions of which that person is unaware.
(D) A person who hums involuntarily can easily learn to notice it and can thereby come to control it.
(E) Not all of Marianne’s opponents are distracted by her humming during chess matches.