Once at the OSS Training and Assessment Facility,the Candidates

Once at the OSS training and assessment facility,the candidates

A) were interviewed by psychologists, completed questionnaires, and sat for paper-and-pencil tests.
B) had their performance evaluated on a highly stressful, but mock interrogation.
C) were challenged to build a small wooden structure using "assistants" who deliberately frustrated the candidates' efforts.
D) All of these