Explanation:

- IGST (Option 1): Correct Answer

- When the service provider and service receiver are in different states, Integrated GST (IGST) is applicable.

- It is charged on inter-state supply of goods and services and is collected by the central government.

- CGST+SGST (Option 2):

- This is applied when both the service provider and service receiver are in the same state.

- Here, Central GST (CGST) and State GST (SGST) are collected.

- SGST (Option 3):

- This is never applied alone. It always accompanies CGST when both the provider and receiver are in the same state.

- CGST (Option 4):

- Like SGST, CGST is not applied alone. It is paired with SGST for intra-state supplies.