The correct answer is: D. Duty drawback.
Duty drawback is a refund of customs duty paid on imported inputs used in the manufacture of exported goods. It is a form of export promotion measure that aims to reduce the cost of exporting goods and make them more competitive in international markets.
Cash assistance is a form of export subsidy that provides direct payments to exporters. It is a less efficient form of export promotion than duty drawback, as it does not target the specific costs of exporting goods.
Marginal value is the additional value that a good or service creates for its buyer. It is not a payment made for goods manufactured and exported.
Deferred payment is a type of loan that allows borrowers to repay the loan over time with interest. It is not a payment made for goods manufactured and exported.