Error in test your knowledge 17.9.b?

I am following the LFS211: Linux networking and Administration course.

I think there is an error in the "test your knowledge " section. Specifically in section "17.9.b Test Your Knowledge 17.2". The question is: "which of the following best describes a Maria DB? "

Your system accepts "An object database" as the correct answer. But in my opinion the good answer should be "A relational database".
Because i was questioning my own knowledge i even looked it up on the website of Maria DB (https://mariadb.org/about
https://mariadb.org/about) where it says: "MariaDB is developed as open source software and as a relational database...."

I also provide a screenshot of the error to go with this post.

Please correct this error and if you feel i am in the wrong please let me know.