Sea-level changes along a coastline may be caused by

1. melting or growth of polar ice caps

2. tectonic uplift

3. all of these

4. tectonic subsidence

3. all of these

Explanation:

Sea level can be changed by the following factors -

Tectonic uplift of the ocean basin will increase the sea level while the tectonic uplift of the coastal region will reduce the sea level.

Hence this option is correct.

Melting of polar ice caps will leads to rise in sea level while growth will reduce the sea level along the coastline,

Hence this option is correct.

Tectonic subsidence also changes the sea level along the coastline so this option is also correct.

Therefore, The correct answer is (3).