51. An iso-profit line represents
a. An infinite number of solutions all of which yield the same profit
b. An infinite number of solutions all of which incurs the same cost
c. An infinite number of optimal solutions
d. A boundary of the feasible region
a. An infinite number of solutions all of which yield the same profit
b. An infinite number of solutions all of which incurs the same cost
c. An infinite number of optimal solutions
d. A boundary of the feasible region