为你解答.
He （C、doesn't need） any help. He can do it all by himself.
他不需要任何帮助.他可以自己做.
解释：need在此为行为动词,主语是第三人称单数,否定式要加doesn't.以下是错误选项分析--
A needs not：错误的否定式,应该加助动词.
B needn't：这是把need当情态动词用,后面还应该有实义动词,句子才完整.
D doesn't need to ask：ask后面缺少了介词for.ask for help,求助.