Concept: Import duty is a tax imposed on goods brought into a country, and its collection is assigned to a specific government agency.
Explanation: Import duty is collected at the point of entry by the customs and excise authority.
This body is responsible for assessing and collecting various customs duties, including import and export duties.
Ports authority handles port infrastructure, not duty collection.
Marketing boards deal with agricultural product sales, not import duties.
Clearing and forwarding agents assist traders but do not collect duties on behalf of the government.
Answer: D. customs and excise authority