What are the deployment options (models) for a company that plans to use on-demand CRM software?

If somebody knows the answer, can you tell me?

a) In-house developed, Outsourced, Proprietary, Off-the-shelf, Open-source b) Application Server Provider (ASP), Single-tenant SaaS, Multi-tenant SaaS, Multi-instance SaaS. c) On-premise, Instantaneous, Full in-house, Hybrid On-premise/On-demand d) Shared On-demand, Private On-premise, Shared On-premise e) The above are NOT deployment options of on-demand CRM!