Which of the Following Problems Are Special Types of Minimum

Multiple Choice

Which of the following problems are special types of minimum cost flow problems?
I. Transportation problems.
II. Assignment problems.
III. Transshipment problems.
IV. Shortest path problems.

A) I and II only
B) I, II, and III only
C) IV only
D) I, II, III, and IV
E) None of the choices is correct.