Answer & Explanation
C) He ate; however, he didn't sleep.
Like commas, semicolons indicate an audible pause — slightly longer than a comma's, but short of a period's full stop.
Rules for Semicolon ::
1. A semicolon can replace a period if the writer wishes to narrow the gap between two closely linked sentences.
2. Use a semicolon before such words and terms as namely, however, therefore, that is, i.e., for example, e.g., for instance, etc., when they introduce a complete sentence. It is also preferable to use a comma after these words and terms.
3. Avoid a semicolon when a dependent clause comes before an independent clause.
4. Use a semicolon to separate units of a series when one or more of the units contain commas.
Hence according to rule no. 2) option (C) He ate; however, he didn't sleep is correctly puctuated with a semicolon.