If a Motorist Is Stranded in Front of a Pay

Multiple Choice

If a motorist is stranded in front of a pay phone and has only dollar bills, and he ends up buying a quarter from a passerby for $1,

A) the stranded motorist must not understand that four quarters are worth $1.
B) economic theory is unable to explain this transaction.
C) both parties have gained from this exchange.
D) the passerby was made better off and the motorist worse off.