Jeffrey decided he could earn a nice profit by developing courses and offering one$-$on$-$one help to older customers in overcoming their technology deficiencies. Although the business struggled at first, he is experiencing a good deal of success now. Jeffrey has many satisfied customers, and the business has grown to the point where he now employs several workers. Jeffrey's experience is an example of

Multiple Choice

$$ the principle of comparative advantage.

$$ the invisible hand concept.

$$ resource development.

socialism at work.