What should Agent Dan do if he feels the buyer cannot afford the property?

Agent Dan should communicate his concerns to Seller Carrie while still presenting all offers. This approach demonstrates professionalism and transparency in real estate transactions. It's crucial for agents to ensure that sellers are fully informed about the financial viability of potential buyers. By sharing his apprehensions about the buyer's affordability, Dan allows Carrie to make a more informed decision regarding the offer.

Additionally, presenting all offers, including the one from the concerned buyer, respects the buyer's position while maintaining ethical standards. This way, the seller can weigh the offer in the context of Dan's concerns instead of being left in the dark, which could lead to potential complications later on if the buyer cannot follow through financially.

Ignoring the concerns or rejecting the offer without consulting the seller would not adhere to best practices in real estate. Advising the buyer to increase their offer does not directly address Dan's concerns about affordability, which could mislead the buyer into overextending themselves financially. Thus, option B is the most responsible and ethical choice in this scenario.