题目选项分析

Ryūnosuke Akutagawa's knowledge of the literatures of Europe, China, and Japan was instrumental in his development as a writer, informing both his literary style and the content of his fiction.

Ryūnosuke Akutagawa's knowledge of the literatures of Europe, China, and Japan were instrumental in his development as a writer, informing both his literary style in addition to the content of his fiction.