What Was the Idea Behind Ronald Reagan's "Trickle-Down" Economics

What was the idea behind Ronald Reagan's "trickle-down" economics?

A) It would help black families by giving them small amounts of money.
B) It gave tax breaks to the wealthy, who were then supposed to spend that money to improve the economy and benefit middle- and lower-class people.
C) It was a very complicated theory that involved a variety of levels of tax increases and decreases, and property taxes to achieve maximum growth.
D) Trickle down economics asserted that water conservation measures needed to be implemented to save money and resources.