Use a supply-and-demand diagram of a competitive market to illustrate the qualitative effects of the following possible shocks in the Italian market for red wine.

a. A new research study shows that red wine helps prevent heart disease, stave off aging, and reduce age-related memory decline.

b. Trade barriers that restricted imports of red wine from countries outside the European Union are eliminated.

c. A recession in Italy causes a decline in per capita income.

d. Genetically engineered wine grapes are created that allow for greater red wine production without increasing cost.