What aspect of muscular fitness is BEST addressed by a client adhering to the following regimen?
a. Frequency: Provide at least 72 hours recovery time between exercises for the same muscle groups.
b. Intensity: Between 70 and 80% of maximum resistance, reaching fatigue between 50 and 70 seconds.
c. Repetitions: Eight to 12.
d. Sets: Three to four sets with 30 to 60 seconds rest between successive training sets.
e. Type: A combination of multi-joint and single-joint exercises using various techniques, including breakdown training and assisted training.

Muscular fitness may be defined as the muscles that has the ability that can lift the heavier objects. The muscle fitness of a body can be improved by doing exercises.

The frequency of muscle fitness can be increased by providing at least 72 hours recover time between the exercise for same muscle group. The muscular fitness increase the time of exhaustion of muscles.

Thus, the correct answer is option (A).