In a story what would cause a character to be considered complex

The most probable thing to cause a character to be considered complex in a story is a change in their behavior due to experience.

Explanation:

A complex character, also known as a round or dynamic character, undergoes changes as the plot of the story unfolds. Those changes, good or bad, are caused by actions or experiences. This type of character advances to plot and has significant interaction with other characters. Complex characters present several traits and emotions, as well as strengths and weaknesses, which may create conflict inside the story.

the middle one

explanation:

because it's about a pauper