-What’s your plan for the holiday Sam?I’ll go on a trip to Beijing with my fam

问题补充：

---- What’s your plan for the holiday, Sam?

----- I’ll go on a trip to Beijing with my family.

------

A. Have fun

B. Good luck

C. Come back soon.

D. Congratulations

答案：

(答案→)A. Have fun

B. Good luck

C. Come back soon.

D. Congratulations

解析：考查交际用语。A玩的开心；B祝你好运；C很快就回来；D祝贺。句意：—sam,你的假期计划是什么？—我将和我的家人去北京旅游？—玩的开心点。根据上文可知对方要去北京旅游，那么应该是祝对方玩的开心，故A正确。