What are the example of being healthy?

Can someone me answer all the questions?

Which of the following  bestillustrates a negative reinforcer?               a.  copland gives up candy to stave off chronic acid indigestion.    b.  nancy learns that she prefers chocolate over vanilla.    c.  carmine changes his major to english lit after failing a math exam.    d.  on a hot day, lindberg always drinks lemonade.

You are the on-duty desk sergeant at the local police station. a man walks in and says, "i killed someone and want to confess." you grab your digital voice recorder and direct the man to a chair. he sits down and tells the tale of what turns out to be a first-degree murder. you record every word, including the numerous instances in which you said, "uh- huh" and "i see." satisfied that the subject did, indeed, commit a murder, you place him under arrest. the confession is: