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 undergoes peer - review, which means experts in the field check its accuracy, methodology, and validity. School textbooks for students may not be focused on multi - age classes specifically. Parenting blogs are personal and may lack academic rigor. Wiki websites, while sometimes useful, can be edited by anyone and may not have the same level of academic scrutiny as a journal article.

Answer:

journal article about classrooms with students of varying ages.