Final answer:
The most commonly cited reason for ending a friendship due to changes in life circumstances is relocation or moving to a different place.
Step-by-step explanation:
The most commonly cited reason for ending a friendship due to changes in life circumstances is A) Relocation or moving to a different place. When someone moves away, it can become more difficult to maintain a close friendship due to distance and the challenges of staying in regular communication. This can result in the friendship gradually fading away over time.