The adverse effects of ice, snow, or frost on aircraft performance include which of the following?

When ice, snow, or frost accumulate on an aircraft, they disrupt the smooth airflow over the wings and other surfaces. This disruption leads to an increased stall speed, as the aircraft will require a higher angle of attack to maintain lift under these conditions. The additional weight and altered shape due to the ice or frost can cause the wings to reach their critical angle of attack sooner than they would under clean conditions, making the aircraft more susceptible to stalling at lower speeds.

In contrast, the other options do not reflect the physical realities of how ice and frost impact aircraft performance. Increased thrust would not typically be associated with adverse weather conditions; rather, the aircraft may actually need more power to achieve sufficient performance. A decreased stall speed contradicts the fundamental aerodynamic principles affected by ice, as lift is compromised, raising the stall speed. Finally, a decrease in aerodynamic drag is not accurate; in fact, ice and frost usually increase drag due to the irregular surfaces they create, which hinders airflow.