when we speak to people ,we should be __A.as polite as possible B,as politely as possible 应选哪...

when we speak to people ,we should be __A.as polite as possible B,as politely as possible 应选哪...
when we speak to people ,we should be __A.as polite as possible B,as politely as possible 应选哪个?并解释为什么