Which of the following statements is false?

A transshipment problem is a generalization of the transportation problem in which certain nodes are neither supply nodes nor destination nodes.

The assignment problem is a special case of the transportation problem in which all supply and demand values equal one.

The objective of the transportation problem is to minimize the number of shipments necessary to satisfy total demand at the destinations.

Converting a transportation problem linear programming from profit maximization to cost minimization requires only changing the objective function; the conversion does not affect the constraints.