If $X _ { \text {iij } }$ Refers to the Number of Hours Employee

If $X _ { \text {iij } }$
Refers to the number of hours employee $f$
Works in week $\int$
,then to indicate that the number of working hours of 4 employees in week 3 should not exceed 160 hours,we must have a constraint of the form

A)
$X _ { 11 } + X _ { 12 } + X _ { 13 } + X _ { 14 } \leq 160$
B)
$X _ { 13 } + X _ { 23 } + X _ { 33 } + { } _ { 43 } \leq 160$
 
C)
$X _ { 31 } + X _ { 32 } + X _ { 33 } + X _ { 34 } \leq 160$
D)
$X _ { 43 } \leq 160$