Match each of the following characteristics or scenarios with either the term negative externality or the term positive externality.
a. Over allocation of resources: (Click to select) Positive externality Negative externality.
b. Tammy installs a very nice front garden, raising the property values of all the other houses on her block: (Click to select) Negative externality Positive externality.
c. Market demand curves are too far to the left (too low): (Click to select) Positive externality Negative externality.
d. Under allocation of resources: (Click to select) Positive externality Negative externality.
e. Water pollution from a factory forces neighbors to buy water purifiers: (Click to select) Negative externality Positive externality.