Answer:
The correct answer is option a.
Explanation:
The monopolist determines their equilibrium quantity and price through the intersection of marginal cost and marginal revenue.
A reduction in fixed costs will change the profits to the monopolist but it will not change the equilibrium price and quantity. This is because the change in fixed costs will not affect marginal revenue and marginal cost.
So even after a change in fixed costs, the optimal; output level remains the same.