Find the minimum and maximum values of z = 4x + 5 y, if possible, for the following set of constraints.

3x + 4y greater than or equals 12

x + 4y greater than or equals 8

x greater than or equals 0, y greater than or equals 0

Select the correct choice below and, if necessary, fill in the answer box to complete your choice.

A. The minimum value is: (Round to the nearest tenth as needed.)

B. There is no minimum value.

A. The maximum value is: (Round to the nearest tenth as needed.)

B. There is no maximum value.