Is it that you often play computers games __worries your parents?A.why B.that C.which D.what

这里是个强调句型的一般疑问句式，可以将句型转换成陈述句型，it is that you often play computers games __worries your parents
将it is that 强调部分去掉，由that 代替实际主语you often play computers games。在后面的句子里做主语

it is that……的句型
主句的陈述句是：it is （that you often play computers games） that worries your parents。
括号里面的that引导一个定语从句修饰后面的that，后面的that引导一个表语从句，在从句里不担任任何成分。
判断在从句里是用why，where，what，which等词的时候，一般就是看他们在语句中但不担任角色。why，what，where除了表达出各自的意思外，一般还应该在句子里做主语或宾语的成分，而that和which一般不担任任何成分，that一般可以和which互换，但是有些特殊情况就不可以，that可以引导表语从句，which不可以。
应该就是这样解释吧

原句是：
that you often play computers games (主语从句）worries（谓语） your parents（宾语）
强调结构句句型是：
It is + 被强调部分+ that-从句
这样可见：被强调的是原句主语

选B 这里是个强调句 原形是 It is that you often play computer games that worries your parents.这里是强调主语从句（that you often play computer games ） 理解了吗？