Which of the following statements about economic sectors are true?
1. A subsistence farmer and a miner both are employed in the primary economic sector.
II. A person who works in a bread factory is employed in the primary economic sector.
III. A construction worker is employed in the secondary economic sector.
IV. An airline pilot is employed in the tertiary economic sector.
A. I., II., III., and IV.
B. I. and III. only
C. I., III., and IV.
D. I., II., and III.