Which of the Following Is NOT an Example of a Developmental

Which of the following is NOT an example of a developmental change?

A) Julius is working on his batting skills, and he hit the ball much farther today
B) Caitlin left out several steps in the process of conducting the lab experiment, but she understands what she did wrong and is redoing the experiment.
C) Mark is walking carefully on one foot while his sprained ankle heals.
D) Milos has learned enough English to introduce himself to other students