Answer:
A. have other characters discuss him of her.
Step-by-step explanation:
Having characters speaking about the main one does move forward the protagonist's arc, since it does not add a relevant layer to his/her actions, reactions, thus, avoiding any possibility of development.
It must be done through him/herself in a variety of ways:
- Have the character speak, behave, think, interact, or respond according to particular situations, which adds layers to his/her personality.
- Add a realistic background which increases the character's relatability.
- Add both flaws and virtues, contradictions and desires, which creates character's complexity .
- Add conflict to the character's storyline, which creates obstacles to achieve his/her goals.