[Scheduling] A department store has decided to stay open on a 24-hour basis. The store manager has divided the 24-hour day into six 4-hour periods. The beginning times for the shifts are 12:00 AM, 4:00 AM, 8:00 AM, 12:00 PM, 4:00 PM, and 8:00 PM. The minimum number of employees required in each period is as follows: 240 from 12:00 AM to 4:00 AM 190 from 4:00 AM to 8:00 AM 250 from 8:00 AM to 12:00 PM 220 from 12:00 PM to 4:00 PM 300 from 4:00 PM to 8:00 PM 215 from 8:00 PM to 12:00 AM Personnel must report for work at the beginning of one of these times and work 8 consecutive hours. The store manager wants to know the minimum number of employees to assign for each 4-hour segment to minimize the total number of employees. [Note: Xi = no. of employees assigned to time period i, where i = 1, 2, 3, 4, 5, and 6 (time period 1 = 12:00 AM 4:00 AM; time period 2 = 4:00 AM 8:00 AM and so on).]

Which of the following is the correct objective function?

A: Which of the following constraints is correct?

Group of answer choices

X1 + X5 < 190

X1 + X2 190

B: Which of the following constraints is correct?

Group of answer choices

X2 + X5 < 250

X2 + X3 250

C: Which of the following constraints is correct?

Group of answer choices

X1 + X6 240

X1 + X5 < 240