A retailer experiences fluctuating traffic during sales events. Which cloud feature should be used to handle the variable load?

Elasticity is the correct choice because it refers to the ability of a cloud system to automatically scale resources up or down in response to demand. For a retailer with fluctuating traffic, elasticity ensures that the system can handle peak loads during sales events by adding resources and then release those resources when demand decreases, optimizing cost and performance. Geo-redundancy focuses on data replication across geographical regions for disaster recovery, not handling variable loads. Load balancing distributes incoming traffic across multiple servers to prevent overload, but it doesn't automatically adjust the number of servers. Agility is a broader concept referring to the ability to respond quickly to change, not a specific feature for handling variable loads.