Which One of the Following Scenarios Best Reflects the Basic

Which one of the following scenarios best reflects the basic idea of individual constructivism?

A) A students receives a sticker from his music teacher when he is able to play the F major scale on his saxophone without any mistakes.
B) Four students in a study group divide the day's reading assignment into four sections. Each student reads a section and then teaches the material to the other group members.
C) A student tries to make sense of a poorly written and confusing magazine article.
D) A student watches his physical education teacher as the teacher shows his class the arm motion for throwing a football.