Out of the following events, which are likely to cause the demand for coffee to increase? Explain

Question:

Out of the following events, which are likely to cause the demand for coffee to increase? Explain your answers.
a. An increase in the price of tea
b. An increase in the price of doughnuts
c. A decrease in the price of coffee
d. The Surgeon General's announcement that drinking coffee lowers the risk of heart disease
e. Heavy rains causing a record-low coffee harvest in Colombia