「どの国の参加者が多いですか」という質問を英訳すると「Which country has the most participants?」または「What is the country with the most participants?」になります。回答は「OO has the largest number of participants, OO has the second largest number of participants, OO has the third largest number of participants…」と言っても良いと考えました。国の名前を入れると「Italy has the largest number of participants, China has the second largest number of participants, England has the third largest number of participants…」になります。