Question

the most reliable source for a presentation about education in multi - age classes would be a
school textbook for students.
parenting blog about student mentors.
wiki website about the history of one - room schoolhouses.
journal article about classrooms with students of varying ages.

Explanation:

A journal article is a peer - reviewed source. It likely contains well - researched and accurate information about multi - age classrooms. Textbooks may not focus specifically on multi - age classes, parenting blogs lack peer - review, and a wiki about one - room schoolhouses has a different focus.

Answer:

journal article about classrooms with students of varying ages.