Acompany has a goal of calling on at least 400 customers a month (goal 1), but no fewer than 260 customers a month (goal 2). if x represents the number of customers contacted, which pair of constraints listed below is the appropriate representation in a goal programming problem? 1) x+ d1-- d1+ 400, x + d2- d2+ 260 2) x+d1--d1+ = 400, x-d2-+d2+-260 4) x-d'i_ + d1+ = 400, x + d2-d2+ = 260