Final answer:
For lesser difficulties, individuals can use behavior principles like positive reinforcement and self-monitoring to adjust their behavior, which is in line with cognitive-behavioral therapy's methods. The correct option is c.
Step-by-step explanation:
When dealing with lesser difficulties, as opposed to significant problems that require professional help, an individual may apply behavior principles on themselves for treatment.
Behavior principles encompass techniques such as positive reinforcement, self-monitoring, and behavior modification strategies that individuals can utilize to adjust and improve their own behavior patterns.
These principles are foundational to cognitive-behavioral therapy (CBT), which aims at changing negative thought patterns to improve behavior and emotions, and can often be implemented without the direct supervision of a therapist. The correct option is c.