What advantage does an encyclopedia have over a periodical as a source for research?

An encyclopedia is more likely to be updated frequently.
An encyclopedia is a better source for details on a topic.
An encyclopedia is more likely to focus on a narrower topic.
An encyclopedia is a better source for background information.

An encyclopedia is a better source for details on a topic.

Explanation:

Encyclopedia entries are a lot longer and more detailed than those periodicals that are published so often in magazines and online journals.

Articles and writings on encyclopedia focus on facts to describe and explain the thing or concept behind the name.

An encyclopedia will go in deeper into the meaning behind the subject, which means encyclopedia articles are written in a way that it goes in much deeper and capable of extracting a greater knowledge of the subject.