Which of These Observations Were Made in the Study "On

Which of these observations were made in the study "On Being Sane In Insane Places?"

A) In four public hospitals, staff spent only 11.3% of their time outside the "cage", a glassed-in area that separated them from the patients.
B) A number of actual hospital patients realized that the pseudo patients were actually sane
C) All but one of the pseudo patients were diagnosed with schizophrenia.
D) All of the above.