__________parents say and do has a life-long effect on their chi

__________parents say and do has a life-long effect on their children.
A、What
B、That
C、Which
D、As
【正确答案】：A
【题目解析】：【考情点拨】考查主语从句。【应试指导】句意：父母的言行对他们的孩子有终生的影响。从句中缺少宾语，排除that，因that在名词性从句中不充当任何成分。which有选择含义，应排除。what符合题意。