What leads to disparities in job ability among police department members?

Disparities in job ability among police department members can indeed stem from a variety of factors, which is why the choice that encompasses all relevant aspects is the most comprehensive and correct answer.

Physical attributes play a role in the various demands of police work. For instance, certain positions or assignments may require a higher level of physical fitness or agility, which can affect how effectively an officer performs their duties.

Mental aptitude is equally important, as it influences an officer's decision-making, problem-solving skills, and ability to handle stressful situations. This aspect can impact an officer's capacity to interact with the community, assess situations, and react appropriately in various scenarios.

Training and education are crucial as well. The quality and extent of training an officer receives can significantly affect their competency on the job. Officers who have undergone extensive training may exhibit greater skill levels and job performance than those with less training.

By recognizing that all these factors contribute to the variances seen within a police department, the answer that includes all three dimensions provides a holistic view of the elements that lead to differences in job ability among officers.