Final answer:
Non-commissioned officers (NCOs) are responsible for training junior NCOs and aiding in developing junior officers, ensuring mastery of PRT drills, exercise activities, and assessments.
Step-by-step explanation:
The responsibility for training junior NCOs and aiding in developing junior officers, ensuring mastery of PRT drills, exercise activities, and assessments falls under the role of Non-Commissioned Officers (NCOs) in the military.
These NCOs are typically experienced soldiers who have achieved a higher rank and possess the necessary knowledge and skills to train and guide junior personnel.
They play a crucial role in fostering the professional growth and development of junior soldiers, helping them become competent leaders, and ensuring their proficiency in physical readiness training (PRT) activities.