Which of the following cloud computing concept(s) is/are related to the pooling and sharing of resources?
(A) Virtual Memory
(B) Service
(C) Virtualization

Explanation

In the standard (NIST) definition of cloud computing, 'resource pooling' — a provider's computing resources being pooled to serve multiple tenants — is achieved specifically through virtualization (C), which abstracts physical hardware into shareable virtual resources. Plain 'virtual memory' is an unrelated OS memory-management technique, and a 'service' (e.g. IaaS/PaaS/SaaS) is simply what the cloud offers, not the mechanism enabling pooling. Hence only (C) is related, option (i).