To be certain that exchange between people is mutually beneficial, we generally assume

A) not all people are free to enter the market at will, but once in they are free to make any offer to trade.
B) all people have complete information about each other's preferences.
C) there are no transaction costs.
D) both B and C
E) both A and B

Mutually Beneficial

A situation or agreement that provides advantages to all parties involved, ensuring that each gains from the interaction.

Transaction Costs

Expenses incurred when buying or selling a good or service, which can include fees, taxes, and other charges beyond the price of the product itself.

Complete Information

A state in which all participants in an economic transaction have full knowledge of the terms, conditions, and outcomes associated with the transaction.