Concept: Rebellion and arrogance in a teenager often relate to emotional changes during adolescence.
Explanation:Kojo is fourteen years old, which is the stage of puberty.
At this stage, young people go through rapid physical and emotional changes.
His rebellious and arrogant behaviour is mainly caused by emotional changes, such as mood swings, a desire for independence, and confusion about identity.
Physical changes alone do not directly cause arrogance towards others.
Answer: D. undergoing emotional changes at puberty.