The correct answer is A. Glossary.
A glossary is a list of terms and their definitions, typically presented in alphabetical order. It is often included in a book or other publication to provide readers with definitions of specialized or technical terms that may be unfamiliar to them.
A reference is a source of information that can be used to verify or support a statement. It can be a book, article, website, or other type of resource.
An index is a list of words or phrases that are used in a book or other publication, along with the page numbers on which they appear. It is used to help readers find specific information in the text.
A summary is a brief statement or account of the main points of something. It is often
used to provide a quick overview of a longer text or to help readers remember the key points of a presentation or discussion.In conclusion, a glossary
is the closest synonym of compendium. A glossary is a list of terms and their definitions, typically presented in alphabetical order. It is often included in a book or other publication to provide readers with definitions of specialized or technical terms that may be unfamiliar to them.