The correct choice is Option 1: 'Before work, wrote down honorifics and customer service phrases in a notebook to practice.' The text explicitly states: 'グエンさんは毎日、アルバイトの前に丁寧な敬語や接客の言葉をノートに書いて一生懸命に練習しました' (Every day before work, Nguyen wrote down polite honorifics and service terms in a notebook and practiced hard). This matches Option 1.