What differentiates public clouds from private clouds in a hybrid model?

In a hybrid cloud model, the defining characteristic that separates public clouds from private clouds is the nature of resource accessibility and organization. Public clouds are designed as shared environments where resources are made available to multiple organizations. This multi-tenant architecture allows organizations to take advantage of the scalability, cost-effectiveness, and ease of access that public clouds provide, without the need for dedicated infrastructure.

In contrast, private clouds are tailored to the needs of a single organization, allowing for greater control over resources, customization, and compliance with regulatory requirements. Since private clouds are designed to serve only one organization, they provide a more secure and stable environment, which is often necessary for businesses dealing with sensitive data.

The other options misinterpret the characteristics of public and private clouds. Public clouds are not limited to a single organization or owned by one entity, they are not specifically available over the internet as a defining characteristic, and they generally offer robust security measures tailored to meet the needs of many different users. In fact, private clouds can often offer higher security levels since they are dedicated to a single organization. Thus, choice C accurately captures the essence of how public clouds function within the hybrid cloud framework.