Asphalt for building roads cannot be laid until the temperature is above 70 degrees for at least five days in a row. Consequently, road construction crews have to be increased during the summer months when they must try to lay as much asphalt as possible. Privately-owned road construction firms would use all but which of the following strategies to recruit workers?

a. Internal transfers.

b. Temporary help agencies.

c. Recalls and rehires from previous years.

d. Word-of-mouth to find temporary workers.

e. All of the above.