The answer is C. using your head
Placebos are fake medications or treatments that can trick your brain into thinking it's better. Often someone will think they are very sick when they actually aren't, and that's dangerous for the mind so people will give them fake medications. Its of cures and things atet will help seasickness and motion sickness are placebos. You could have a moral dilemma about wether it's actually helping you or if it just feels like it does.
The answer is obsessive-compulsive disorder. Compulsive and usually unwanted thoughts and actions (rituals) are the common features of the disorder. Although OCD is usually associated with repeating the actions over and over, such as obsessive hand-washing or having to flick a light switch a certain number of times, many people who suffer from OCD struggle with frequent unwanted thoughts and images.