— What's your best friend like? 

—  ___________. [ ]

A. He likes Maths

B. He likes swimming

C. He is a teacher

D. He is polite and has a round face

明末清初思想家唐甄在《太子》篇中说：“凡教太子，观于桑，则知衣服所自出；观于肆，则知器用所自出。凡教太子，过市，则见贩鬻之劳；在途，则见负担之劳。”该言论反映了唐甄的治国思想是（）

A.关注下层民众的疾苦

B.重视农工，勤俭治国

C.民富是国富的前提

D.全面关注社会经济