Explanation:

- The Bharatmala project is an ambitious road and highway development initiative by the Indian government.

- Economic Corridors aim to enhance connectivity between India’s key economic zones, facilitating trade and commerce.

- Border Roads and International Connectivity Roads focus on strengthening connectivity in strategic border areas, enhancing national security, and promoting cross-border trade.

- Coastal Roads and Port Connectivity work on improving links to ports and boosting maritime trade.

- Unfinished projects under NHDP have been incorporated to ensure continuity and completion of existing infrastructures.

The correct option is:

- Option 4: All of the above