Final Answer:
B. Frost spoils the smooth flow of air over the wings, thereby decreasing lifting capability.
Step-by-step explanation:
Frost is considered hazardous to flight because it disrupts the smooth flow of air over the wings, leading to a decrease in lifting capability. When an aircraft's wings accumulate frost, it alters the aerodynamic characteristics of the airfoil. The irregular surface created by frost disrupts the laminar flow of air over the wings, causing turbulent airflow. This turbulence results in increased drag and reduced lift, compromising the overall performance and safety of the aircraft.
Pilots must be cautious about the presence of frost on critical surfaces, such as wings, to avoid adverse effects on aerodynamics, which can lead to difficulties in takeoff, reduced maneuverability, and increased stall speeds during flight.
Option B is the answer.