The way to start is by contacting the Subsidiary Rights Department at the book or novel's publisher. You can usually find the contact information for the Subsidiary Rights Department down in the fine print at the bottom the publisher's website, or by calling the publisher directly.
An agreement granting a producer or production company an option to acquire certain rights in an individual's life story for use as the basis of a theatrical motion picture, television (TV), or streaming production.
An option agreement is made between a writer and a producer and grants the producer an exclusive option to buy the rights in the writer's work. A “shopping” agreement allows the producer to represent the work but gives the producer fewer rights than an option and typically lasts for a shorter period.