In a Minimum Cost Network Flow Model,the Flow Balance Constraint $\geq$

Multiple Choice

In a minimum cost network flow model,the flow balance constraint for each supply node takes the form

A) Flow in
$\geq$ Flow out + Net supply
B) Flow out
$\geq$ Flow in + Net demand
C) Flow in = Flow out
D) Flow out
$\leq$ Flow in + Net supply
E) Flow in
$\leq$ Flow out + Net demand