Which of the Following Approaches Would Be Least Obtrusive in Regard

Multiple Choice

Which of the following approaches would be least obtrusive in regard to measuring the impact of the above group work intervention on school performance?​

A) ​Obtain grade, attendance, and conduct data from school records.
B) Observe the student's in-class behavior yourself.​
C) With the client's permission, obtain videotapes of the child's in-class behavior.​
D) Interview the child.​