【单选题】Mickey is considering buying a tape recorder. His utility function is U(x;y; z)=x+f(y)z:5 where x is the amount of money he spends on other goods, y is the number of tape recorders he buys, and z is t...
A.
He should buy a tape recorder at these prices, but if tapes were any more expensive, it would not pay to buy one.
B.
He should not buy a tape recorder.
C.
He is indifferent to buying a tape recorder or not.
D.
There is not enough information here for us to be able to tell.