If cleared to "Descend Via" a published STAR, what must a pilot comply with?

When a pilot is cleared to "Descend Via" a published Standard Terminal Arrival Route (STAR), it is essential to comply with the published altitude crossing restrictions and speeds outlined in the STAR. This instruction indicates that the aircraft should follow the specific vertical path defined by the STAR, conforming to any altitude limits or crossing points required to ensure safety and efficiency in air traffic management.

The STAR is designed to facilitate orderly arrivals, and adhering to these restrictions helps maintain separation from other aircraft, as well as smooth integration into the approach phase of flight. This means that a pilot must descend at appropriate rates and adjust speeds as necessary throughout the STAR route, while observing the elevations specifically indicated.

In contrast, other options do not fully encompass the comprehensive requirements associated with the "Descend Via" clearance. Just focusing on altitude restrictions alone does not account for speed adjustments also mandated by the STAR. Instructions from ATC after the clearance could change the previously established flight path or requirements and are not predetermined by the published STAR. Lastly, stating that there are no restrictions after being cleared is inaccurate since the essence of a "Descend Via" clearance is to adhere strictly to those specific published parameters.