Final answer:
Following resistance training, increased neural drive to the musculature is primarily due to increased agonist muscle recruitment and greater synchronization of motor units; muscle hypertrophy is not a direct factor in this neural adaptation.
Step-by-step explanation:
Following resistance training, increased neural drive to the working musculature is the result of several neural adaptations including: (I) increased agonist muscle recruitment, (III) improved firing rate, and (IV) greater synchronization of motor units. These adaptations facilitate the performance of resistance exercises. Increased agonist recruitment involves activating more motor units to produce a stronger muscle contraction. Improved firing rate refers to the increased frequency of action potentials, which can lead to more powerful contractions through a process known as complete tetanus, where the muscle contractions become continuous due to a very high stimulus frequency. Greater synchronization of motor unit firing can enhance the force produced during a contraction by coordinating the activation of motor units so their forces are summed more effectively.
Muscle hypertrophy, although a key result of resistance training, is not a direct factor in the mechanism of increased neural drive, but rather a physical adaptation of the muscles, including increases in the number of sarcomeres and myofibrils, leading to an increased muscle mass.
Therefore, the correct answer to the student's question is: b) I and IV - increased agonist recruitment and greater synchronization.