The correct answer is public cloud. In public cloud models, a provider (such as AWS, Azure, or Google Cloud) hosts infrastructure and services that are shared across multiple customers, known as multitenancy. Each tenant is logically isolated, but physical infrastructure is shared, allowing providers to achieve economies of scale.

A. Private cloud is dedicated to one organization, not multitenant.

B. Community cloud is shared among organizations with common interests, but it’s less common than public multitenancy.

D. Hybrid cloud combines private and public but does not define tenancy alone.

Public cloud services are the most cost-effective and scalable because they spread costs across many customers, but they require strong security and isolation to protect tenants.

References (CompTIA Network+ N10-009):

Domain: Networking Concepts — Cloud models, multitenancy, public vs private.