Question

------he needs now is something that can make him feel better Awhat that B that what C all

Answer 1

选择C all
这句话意思是：他现在所需要的是能够使他感到好受一些的东西。
All he needs now是主句主语，is是主句系动词，something that can make him feel better是主句表语。主语all是先新词，he needs now是定语，修饰先行词all，因为先行词all做的是needs的宾语，所以引导词that可以省略，all （that）he needs now；表语something that can make him feel better，something是先行词， that can make him feel better是定语从句，修饰先行词something，something在定语从句中做的是主语，that是定语从句引导词。整个句子简化以后是：All is something。he needs now 是修饰All的，that can make him feel better 是修饰something的。
如果用what，可以这么说：What he needs now is something that can make him feel better .
那么这个时候，What he needs now 是主句主语，is是主句系动词， something that can make him feel better 是主句表语。What he needs now是个主语从句，what是主语从句的引导词，做的是needs的宾语；something that can make him feel better 跟第一种情况下是一模一样的。
希望帮助到你，学习进步。

Answer 2

C