Which of the following suffixes relates to a person involved in a specific medical practice?

The suffix that indicates a person who is engaged in a specific medical practice is "-ician." This suffix is commonly found in terms such as "physician," which refers to a doctor or medical professional who practices medicine. The use of "-ician" signifies an expert or specialist in a particular field, especially within the medical domain, establishing a connection between the practice and the individual's role.

The other suffixes do not share this specific connotation. For instance, "-ile" often denotes capability or tendency but does not refer to a practitioner. Similarly, "-ion" indicates the process of doing something rather than the person who does it. Lastly, "-ical" relates more to characteristics or properties and is frequently used to form adjectives associated with fields, rather than to specify a profession or individual in practice. Thus, "-ician" is exclusively suited to denote individuals involved in medical practices.