Answer:
The correct answer would be, Bill and Cathy.
Step-by-step explanation:
The law of proximity states that when there are assortment of objects, then the objects that are close to each other form a group. Proximity promotes interactions between people and groups. These interactions usually end in liking or disliking between the people or groups.
So because Bill and Ally have been in chat with each other and had known each other well, even then Bill urged to chat with Cathy, which means he had a lower interest in Ally, and when he chatted with Cathy, then according to law of proximity, there are more chances of Bill and Cathy to like each other and make a couple.