Pilots shall not operate below Minimum Descent Altitude (MDA) or continue below Decision Height (DH) unless certain requirements are met. What are the key conditions and criteria that must be satisfied before a pilot can descend below MDA or continue below DH during an approach?
A) Positive communication with air traffic control
B) Visual reference to the required runway environment
C) Approval from the airline's operations center
D) GPS navigation system alignment with approach waypoints