Answer:
The answer is B. Exercise.
Step-by-step explanation:
Exercise is one of the easiest and most effective ways to improve concentration, motivation, memory, and mood. Physical activity immediately boosts the brain's dopamine, norepinephrine, and serotonin levels—all of which affect focus and attention. Exercise causes blood to flow to the brain, which activates a person's neurons and promotes cell growth, particularly in the hippocampus.