Who Is Included and How Is the OSDUHS Conducted

Who is included and how is the OSDUHS conducted?

A) Interviews include thousands of students every second year from elementary and secondary schools across Ontario
B) Interviews include thousands of students every second year from secondary schools across Ontario
C) Interviews include thousands of students from colleges and universities every second year from across Ontario was
D) Interviews include thousands of students every second year from colleges and universities, and elementary and secondary schools, across