一道英语练习题!As a doctor,he tries his best to help__A the sick B

A
the sick指病人,其它不是!例句：
Moral responsibility is the burden of the sick as well the healthy .
担负起道德责任不仅是健康人的职责,也是患者的义务.
Infants ,children ,pregnant and lactating women ,the sick ,and the elderly are very vulnerable to malnutrition and have special needs .
婴儿、儿童、孕妇和哺乳妇女、病人以及老人非常容易患上营养不良,他们都有特殊的需要.