Given the Following Linear Programming Problem with Two Non-Negative Variables $\left(X_{1}\right.$

Given the following linear programming problem with two non-negative variables $\left(X_{1}\right.$ and $\left.X_{2}\right) , 3$ constraints (all $\leq$ type) , and a maximize objective function $\left(Y_{i}\right.$ , where $i=1,2,3$ , respective to the dual variables associated with constraints 1,2 and 3 ) ,
Max: $250 X_{1}+500 X_{2}$
Constraints: $X_{1} \leq 320 \quad 2 X_{1}+5 X_{2} \leq 1100 \quad 1 X_{1}+1.2 X_{2} \leq 480$
Variables are non-negative the variables of the dual problem are required to be

A) strictly negative
B) non-negative
C) strictly positive
D) non-positive