Final answer:
c. decrease. The equilibrium price of wine will decrease when supply decreases and demand increases.
Step-by-step explanation:
The equilibrium price of wine will decrease.
According to the information given, many farmers have stopped planting new grape vines and have switched to growing other crops. This implies that the supply of grapes used to produce wine has decreased. However, the article also mentions that Americans have continued to consume more wine, indicating an increase in demand. When supply decreases and demand increases, the equilibrium price of wine will decrease. This is because there is less supply available, but the demand remains high, causing prices to fall.