Step 1: Understanding the Concept:
An "Entrepot" is a port, city, or trading post where merchandise may be imported, stored or traded, and typically re-exported without paying import duties.
Step 2: Detailed Explanation:
1. Singapore: It is the prime example of an entrepot port in Southeast Asia, acting as a collection and distribution center for goods moving between the West and the East.
2. London and Rotterdam: Rotterdam is the primary entrepot for Europe, and London has historically served this role for goods arriving from overseas for distribution across the continent.
Step 3: Final Answer:
All the ports listed—Singapore, London, and Rotterdam—function as centers where goods are collected from various countries and redistributed/re-exported. Therefore, (D) is the correct choice.