Question

identify the characteristic that distinguishes the scapulocostal joint from the other joints in the shoulder complex: it is the largest joint in the complex it lacks a joint capsule it connects the clavicle to the sternum it forms the shoulder proper

Explanation:

The scapulocostal joint (also called the scapulothoracic joint) is a functional joint, not a true synovial joint. Unlike other shoulder complex joints (like the glenohumeral, acromioclavicular, and sternoclavicular joints), it does not have a synovial joint capsule. The other options are incorrect: the largest shoulder joint is the glenohumeral joint; the sternoclavicular joint connects clavicle to sternum; the glenohumeral joint is the shoulder proper.

Answer:

It lacks a joint capsule