Final answer:
According to Hall, the primary concern of no teams reaching the summit was probably avalanches or altitude sickness due to harsh conditions like low oxygen and cold at high altitudes, which can result in acute mountain sickness.
Step-by-step explanation:
The main concern that arose because no team had been to the summit yet that year, according to Hall, was likely the danger of avalanches or altitude sickness. Climbers on Mount Everest face extreme conditions including cold, low oxygen levels, and low barometric pressure, which are hostile to human life. Exposure to high altitudes with low partial pressure of oxygen in the air can lead to acute mountain sickness (AMS), characterized by headaches, disorientation, fatigue, nausea, and lightheadedness.