North American Adolescent Boys Have Higher Self-Esteem Than Adolescent Girls

North American adolescent boys have higher self-esteem than adolescent girls. Research suggests that this disparity is probably MOSTLY due to the fact that ____.

A) girls tend to be more modest when filling out surveys
B) self-esteem surveys are heavily gender-biased
C) girls regard themselves as less intelligent than boys
D) girls tend to be more critical of their bodies than boys