Answer:
The Tax is a lump-sum which means that it does not change by output. It is therefore a fixed cost.
Average Fixed Cost ⇒ INCREASE
The new tax would increase the fixed costs which would lead to an increase in the average fixed costs.
Average Variable Cost ⇒ UNCHANGED
The tax is a fixed cost not a variable cost which means variable costs will not be affected.
Average Total cost ⇒ INCREASE
Fixed costs is a part of total cost and if that increases, the total cost will have to increase as well.
Marginal Cost ⇒ UNCHANGED
As the cost that changed is a fixed cost, the total cost will not change as a result of more production so marginal cost will not change.