Final answer:
The author of the book of Hebrews is unknown, the occasion for writing the book is persecution, the literary form is a sermon, and the main themes are the superiority of Christ and the fulfillment of the Old Testament law through Christ.
Step-by-step explanation:
The author of the book of Hebrews is unknown, making option b) Author: Unknown the correct choice. The occasion for writing the book is believed to be persecution, which is in line with option b) Occasion: Persecution. The literary form of the book of Hebrews is a sermon, as it contains strong exhortations and persuasive arguments, supporting option b) Literary Form: Sermon. The main themes of the book of Hebrews are the superiority of Christ and the fulfillment of the Old Testament law through Christ, aligning with option b) Themes: Superiority of Christ.