Final answer:
The sentence requires an em dash for proper punctuation.
Explanation:
The correct punctuation for the sentence is:
- Everyone knows he is the best cook—however, he refused to enter the contest.
This sentence requires an em dash to properly connect the two clauses. An em dash is stronger than a comma and adds emphasis. In this case, it sets off the contrasting idea that follows.
Learn more about Punctuation in English sentences here:
https://brainly.com/question/36650842
