Final answer:
When a tax is imposed on buyers, the equilibrium price paid by the consumers decreases and the equilibrium quantity also decreases.
Step-by-step explanation:
In the market, when a tax is imposed on buyers, it shifts the demand curve downward by the amount of tax, as buyers are willing to purchase less at any given price. This leads to a decrease in both the equilibrium price paid by the consumers and the equilibrium quantity. Therefore, the correct answer is d.