The graph shows the price of a good compared to the quantity demanded and the quantity supplied. on this graph, the bottom horizontal line represents an ineffective price floor set above equilibrium. an effective price floor set below equilibrium. an ineffective price ceiling set above equilibrium. an effective price ceiling set below equilibrium.

Answer D: Effective price ceiling set below equilibrium.

Explanation:

It is correct on edge.

option d is correct. corroborated sources of historical evidence   is necessary to validate a claim about an event in history.

historians tend to use written sources, but audio and visual materials as well as artifacts are important objects that supply information to modern historians.

historical sources are usually divided into two categories: primary and secondary sources. depending on the historian's intent, some sources shift their designation. determining what type of sources toimplement, and the level of credibility and reliability of those sources, is a significant step in critical thinking for the historian.

explanation:

i think the answer is b.