In Ms. Ceyner's class, she encourages students to focus on mastering a task for its own sake and she praises individual performance improvement rather than comparisons to other classmates. By doing this, Ms. Ceyner is

A) reducing failures by pointing out where corrective action is needed.
B) showering her students with compliments in order to make them feel better about themselves.
C) emphasizing ability over effort.
D) fostering a mastery-oriented approach.

D