<span>confidence placed in a person by making that person the nominal owner of property to be held or used for the benefit of one or more others.
So I would go with B</span>
Marginal costs. Keep in mind that marginal means on the edge of something, so the cost of producing one more unit would be on the edge. Hope this explanation helps.
But what What is it that I answer
Education reform lead by Horace Mann was a major reform movement in the early 1800's. He helped create mandatory public education for all in the United States.
