Equilibrium Quantity Will Unambiguously Decrease When

Equilibrium quantity will unambiguously decrease when

A) demand increases and supply does not change,when demand does not change and supply decreases,and when both demand and supply decrease.
B) demand increases and supply does not change,when demand does not change and supply increases,and when both demand and supply decrease.
C) demand decreases and supply does not change,when demand does not change and supply increases,and when both demand and supply decrease.
D) demand decreases and supply does not change,when demand does not change and supply decreases,and when both demand and supply decrease.