Answer:
The prefrontal cortex
Step-by-step explanation:
The prefrontal cortex, which is responsible for higher-order cognitive functions such as decision-making, planning, impulse control, and reasoning, is generally the slowest area of the brain to develop. Its development continues into early adulthood, with significant changes occurring throughout adolescence. This delayed development of the prefrontal cortex is often associated with the development of executive functions and the ability to make complex decisions, which is why teenagers and young adults may sometimes exhibit impulsive behavior or have difficulty with long-term planning.