Which Is an Example of Movement of Factors of Production

Multiple Choice

Which is an example of movement of factors of production between countries within an industry?

A) an employee quitting work in an automobile firm in the U.S. and joining another
B) an employee moving from a steel firm to an automobile firm in the U.S.
C) an employee moving from one steel firm to another in a different country.
D) an employee moving from a steel firm to an automobile firm in a different country.