The correct answer is B. Textbook glossary
Step-by-step explanation:
A glossary is a list of words alphabetically organized and each with definition and in some cases an example or further information. Glossaries are usually related to some specific topic, subject or knowledge area which means different to dictionaries glossaries do not include all the words of one language, but just words related to some topic. Because of this, it is common to find a glossary at the end of scholar textbooks that includes all the words related to the topic and that helps students to understand the content of the book. Considering this, if you want to learn the definitions for unfamiliar words in a science class the best option is to look for the textbook glossary as in the glossary you will find only words related to science, and therefore related to your science class, also this might include examples or extra information you will probably not find in a dictionary or other similar sources.