Use the following diagram for the following three problems:

Assume the notation A$3,$ B$1,$ B$2,$ B$3,$ C$1$ denotes the tons moved from Supplier A to Plant $3,$ Plant $1,$ and Plant $2,$ respectively. The diagram shows the only possible paths between Suppliers A$,$ B$,$ C and Plants $1,2,$ and $3$ with the associated cost per ton. The available supply at the $3$ suppliers and requirements at the $3$ plants are also shown in tons. Define the following decision variables:

A$3$: amount of shipping from supplier A to plant $3$

B$1$: amount of shipping from supplier B to plant $1$

B$2$: amount of shipping from supplier B to plant $2$

B$3$: amount of shipping from supplier B to plant $3$

C$1$: amount of shipping from supplier C to plant $1$

$3.$png

What is the supplier constraint for Supplier C$?$

Group of answer choices

C$1+$ C$2+$ C$3<=500$

C$1=500$

C$1<=500$

C$2+$ C$3<=500$