Theoptimum tariff is:

a. the best tariff a country can obtain via a WTO negotiated round of compromises.

b. the tariff, which maximizes the terms of trade gains.

c. not practical for a large country due to the likelihood of retaliation.

d. the tariff, which maximizes the difference between terms of trade gains and terms of trade loses.

e. not practical for a small country due to the likelihood of retaliation.

Which option is correct?