Step 1: Define justifications. {External justification} refers to doing a behavior because of outside pressures/rewards (e.g., big prize; harsh penalty). {Internal justification} means aligning attitudes to justify one’s behavior when external pressure is insufficient.
Step 2: Dissonance prediction. When rewards/punishments are {large}, people can attribute their behavior to external causes, so they experience little dissonance and need only a {small} change in attitude. Conversely, {small} rewards/punishments produce insufficient external justification, prompting larger internal attitude change.
Step 3: Choose the option. Therefore: \(\underline{external}\) justification; \(\underline{small} \)attitude change \(\Rightarrow\) (D).
Final Answer: (D)