Final answer:
The average geographic range for an 802.11a antenna is closest to 100 meters (option B) under ideal conditions, but it is officially up to 120 meters outdoors and around 35 meters indoors.
Step-by-step explanation:
The average geographic range for an 802.11a antenna is approximately 35 meters indoors and up to 120 meters outdoors under ideal conditions, but this is often less due to interference and obstructions. The options provided in the question do not accurately represent the typical range of an 802.11a antenna.
However, to answer a similar formatted question where the correct choice is among the provided options, and assuming the question is referring to ideal outdoor conditions without obstructions, the closest answer would be:
It's important to note that various environmental factors such as physical obstructions and interference from other devices can significantly affect the effective range.