Answer:
A. shortage of a good or service
Step-by-step explanation:
Shift in demand curve to the right, when supply is constant shows that there is increase in demand. This will lead to increase in price of a good or service.
This indicates that there is shortage in supply of the good or service. Whatever quantity of the good or service supplied, would be bought at high price, since demand increases.
Therefore, at $7.00, which is the new equilibrium price, there is shortage of a good or service, as a result of increase in demand.