Andrea is a typical 11-year-old whose growing self-consciousness and self-criticism drive her to frequently compare herself with her peers. If Andrea is like most children, such comparisons will
decrease her self-esteem

C) reduce her self-esteem.  

Explanation:

Comparison and social-comparison is a typical part of middle-school-aged children. It is at these ages that children develop self-consciousness and self-concept, and start observing people around them as well.

With this, it starts the comparison of us versus them. This kind of thinking can easily reduce or decrease self-esteem - if the child puts too much emphasis on what the others are doing, and starts noticing all the little things that are seemingly wrong or different about themselves, they will become too self-conscious, critical and cynical, and they will develop bad self-esteem.

They will start to see all the good things about others, while comparing it to all bad things they notice about themselves, develop black-and-white thinking, and start having very low confidence.