A.8pmto10pm
B.4pmto6pm
C.2pmto4pm
D.8amtonoon
A.Thenumbersofmaleandfemaleparticipantsareequal
B.Participantswereaskedtoinvolveintheresearchforfourteendays
C.Theabsent-mindedactionsoftheparticipantsarerandomlypresented
D.Theparticipantswererequiredtofinishaquestionnairefortheresearch