The sole legal right held by the author to publish his book is
Answer Details
The author's sole legal right to publish his book is copyright.
Copyright is a legal right that gives the author control over how their work is used and distributed. This includes the right to publish their book, as well as the right to control who can make copies of it, distribute it, and create adaptations of it. Copyright law helps to protect the author's creative work and ensures that they are properly credited and compensated for their efforts.