💡 Detailed Explanation
The correct choice is 'かわりに' (kawari ni - instead of / in place of). The noun '代理' (dairi) means representation or proxy. Therefore, '代理で' (as a representative/proxy) is functionally equivalent to '〜のかわりに' (instead of...). Sentence translation: 'I came in place of my father.' The other choices are: 'あとで' (later on), 'ために' (for the sake of / because of), and 'ついでに' (while I'm at it / taking the opportunity).