I'll take you up on that.

お言葉に甘えます I’ll take you up on that (offer) 「take up」 は「応じる」という意味で、「あなたの申し出に応じる＝take you up on that offer」となります。 A: It is hot outside today, so I can take you to the station. B: Really? I’ll take you up on that. Thanks. A: […]