Correct answer: option a
Rational:
1. Reciprocal interaction: it refers to an action which individual or objects exhibits similar behavior either at same time or in a back and forth manner. This requires both party interact to produce the desired outcome. So option a is correct.
2. Reaction is something done or felt to a stimulus or event. So its incorrect.
3. Interaction deals with kind of action occur with two or more subjects. So its incorrect.
4. Actions occurs at same time is called simultaneous action. So its incorrect.
Daniel believes that external stimuli are responsible for all human actions and reactions. Accordingly, he believes...