The ________ reflects the approximate change in the objective function resulting from a unit change in the quantity (right-hand-side) value of the constraint. 

A production of 300 units of Twiddle Bugs, an educational toy for children, must be completed within 1 week by BugU Manufacturing. Two production lines are available, each for 30 hours during the week. Production line 1 can produce five units per hour and production line 2 can produce four units an hour. Line 1 costs $50 per hour to operate and line 2 costs $55 per hour. Overtime is available for line 1 at $15 per hour and for line 2 at $12 per hour. Management goals in decreasing order are:

P1: Produce 300 units.

P2: Maximum allowable overtime of 6 hours for line 1.

P3: Cost of overtime must not exceed $750.

P4: Avoid the underutilization of either production line. Assign weights that are proportional to their production capability.

P5: Producing more than 300 units is 1-1/2 times as undesirable as producing under 300 units.

What are the constraints for this problem?