According to O*NET, what is the most common level of education earned by Librarians?

The correct answer is D. Master’s degree.

Most librarians hold a Master’s degree in Library Science (MLS) or a related field, which is typically required for advanced positions in library services. This level of education provides them with the necessary skills and knowledge to manage library resources and assist patrons effectively. If you need more details or have additional questions, feel free to ask!