Concept:
To change a present simple sentence into an interrogative form, use the auxiliary verb \textit{do/does} at the beginning of the sentence.
Explanation:
The subject “He” is third person singular, so we use \textit{does}. When \textit{does} is used, the main verb returns to its base form. Therefore, “enjoys” becomes “enjoy.”
Hence, the correct interrogative form is: Does he enjoy reading historical novels?