I would have to say C, because a glossary is used to find definitions of words and spelling, so I can't see any other answer being correct. Hope this helps! :)
D) determining the meaning of an unfamiliar science word
Explanation:
A Glossary is <em>"an alphabetical list of terms or words found in or relating to a specific subject, text, or dialect, with explanations; a brief dictionary"</em>. If you're reading about an specific scientific subject, the words that they use might carry different meanings than those you're used to. Or maybe you don't know the word at all. Both of those situations can be solved with a glossary.
