💡 Detailed Explanation
The correct choice is 'じかん' (time). The phrase '約束の時間' (yakusoku no jikan) refers to the agreed appointment time. Sentence translation: 'The train stopped due to an accident, and I ended up being late for the appointment time.' 'よてい' (plan) would be '予定に遅れる' but is less idiomatic with '約束の...' than '約束の時間'. 'りゆう' (reason) and 'つごう' (convenience) are grammatically and contextually incorrect.