Answer:
Participants who knew that they had been given adrenaline attributed their physical arousal to the situation.
Step-by-step explanation:
Schachter and Singer's theory is also known as two factor theory of emotions. This theory states that people experiencing emotions and identifying these emotions is a result of both cognitive interpretations as well as physiological arousal of their physical state.
According to Schachter and Singer' theory people who are injected with adrenaline attributed their behavior and physical arousal to the situations.
Thus the answer is --
Participants who knew that they had been given adrenaline attributed their physical arousal to the situation.