Which cloud concept describes this functionality?

Explanations:

Availability refers to the uptime and accessibility of resources, ensuring they are operational when needed, but does not involve automatic scaling or resource management.

Elasticity is the ability of a cloud environment to automatically scale resources up or down based on demand, which perfectly describes the company’s requirement.

Durability refers to the ability of a system to maintain data integrity over time, ensuring that data is not lost, but it does not involve resource allocation or scaling.

Reliability refers to the consistency and dependability of a service or system, ensuring it performs as expected, but does not pertain to the dynamic allocation of resources.