💡 Detailed Explanation
The correct answer is 慎重 (shinchō), meaning 'cautious' or 'prudent'. The context requires careful judgment. '身長' (shinchō) means 'height'. '新調' (shinchō) means 'to make or buy something new'. '深長' (shinchō) means 'profound' or 'significant', which does not fit the context of making a decision in this manner.