💡 Detailed Explanation
The noun '階段' (stairs) is read as 'かいだん' (kaidan). Sentence translation: 'Because the elevator is not working, let's go up the stairs.' '階' is read as 'かい' (kai) and '段' (step/grade) is read as 'だん' (dan). 'ざん' or voiced 'がい' are incorrect.