One Intervention That Has Been Successful at Reducing Girls' Misconception

One intervention that has been successful at reducing girls' misconception that they are not as good at math as boys are is to

A) put girls in advanced math classes and let them see for themselves that they are as capable as boys are.
B) provide out-of-the-classroom math activities and experiences for girls.
C) teach girls that the brain is like a muscle that can grow and change with use, not something that is fixed and unchangeable.
D) tell girls that all they need to do to succeed is to work harder.