Which of the following statements are true about IP multicast service models?

In the SSM model, an (S, G) entry is generated for each source-group pair.

In the SSM model, different multicast applications on the same source can use the same SSM group.

Multicast service models differ for receiver hosts but do not affect multicast sources.

In the ASM model, an ASM group can be used by only one multicast application.