The correct answer is A. dissuade.
To dissuade someone is to discourage them from doing something. It is the opposite of cajole, which means to persuade someone to do something by using flattery, charm, or deception.
B. Detract means to reduce the value or importance of something. It is not the opposite of cajole because cajole does not necessarily reduce the value or importance of something.
C. Disclose means to make something known or public. It is not the opposite of cajole because cajole does not necessarily involve making something known or public.
D. Confide means to tell someone something secret or private. It is not the opposite of cajole because cajole does not necessarily involve telling someone something secret or private.
In conclusion, the correct answer is A. dissuade.