How did psychologists decide which MMPI items belong on the schizophrenia scale?

a. They used questions that people with schizophrenia answered differently from others.
b. They used questions that pertained to the major theoretical views of schizophrenia.
c. They took statements by patients with schizophrenia and made them into questions.
d. They chose statements that caused conflicting activity in more than one brain area.

a