Answer:
d. decreases; is unknown
Explanation:
Substitute goods are goods that can be used in place of each other.
The news of the health benefits of maple syrup would reduce the demand for corn syrup.
The government subsidy would increase the supply of corn syrup.
As a result the equilibrium price would fall and the effect on equilibrium quantity would be indeterminate. It would depend on the extent of change of demand and supply.
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