A. because other characters thoughts or opinions of a character cannot help develop that character. Character development had be expressed through the character himself.
<em><u>A. have other characters discuss him of her.</u></em>
Explanation:
<u>Having characters speaking</u> 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 <u>development</u>.
It must be done through him/herself in a <u>variety of ways</u>:
Have the <u>character</u> speak, behave, think, interact, or respond according to particular situations, which adds layers to his/her personality.
Add a <u>realistic background</u> which increases the character's relatability.
Add both flaws and virtues, contradictions and desires, which creates <u>character's complexity</u>
.
Add <u>conflict</u> to the character's storyline, which creates obstacles to achieve his/her goals.