The fixed costs of each facility as well as the cost of shipping between regions is shown in the table below. The decision variables are defined as follows: Xij = quantity shipped from supply region i to demand region j. i = 1, 2, 3, 4 and j = 1, 2, 3, 4. Yik = 1 if facility k is selected for supply region i; 0 otherwise, where i = 1, 2, 3, 4 for each supply region; k = 1 (low capacity facility) or 2 (high capacity facility) The constraint for the South Asia demand region is: Question 15 options: X31 + X32 + X33 + X34 =7. X13 + X23 + X33 + X43 = 7. X13 + X23 + X33 + X43 7. X31 + X32 + X33 + X34 7