Final answer:
The frontal lobes are responsible for higher mental functions such as planning, personality, memory, and decision making. They include the prefrontal cortex which is key for executive functions and the motor cortex for planning movements.
Step-by-step explanation:
The area of the brain that is responsible for higher mental functions such as planning, personality, memory, and decision making is the frontal lobes (C). The frontal lobes, and particularly the prefrontal cortex, are associated with executive functions which include aspects of personality, attention, working memory, and various cognitive functions that direct behavior toward achieving goals. Moreover, the frontal lobe includes regions that control motor functions, such as the motor cortex, which is involved in planning and coordinating movement, as well as socialization, speech, and decision-making.