Explanation:

- Bay of Bengal Initiative for Multi-Sectoral Technical and Economic Cooperation (BIMSTEC) is an international organization that focuses on regional cooperation between its member countries.

- The abbreviation BIMSTEC stands for:

- Bay

- Initiative

- Multi

- Sectoral

- Technical

- Economic

- Cooperation

- Correct Answer: 3. Sectoral

- In BIMSTEC, 'S' stands for Sectoral. This reflects the organization's focus on multiple sectors, such as technology, trade, and economic development among its member states.

- Other Options Explained:

- Option 1: Strategic - Would imply a focus on strategic aspects, which doesn't align with BIMSTEC's multi-sectoral aim.

- Option 2: Structural - Suggests an emphasis on structure, not relevant to BIMSTEC's operational focus.

- Option 4: Social - Relates to social aspects, which are not specifically the focus of BIMSTEC.

- Option 5: Symbolic - Indicates representation or symbolism, not directly related to the purpose of BIMSTEC.