A retail company sees massive website traffic spikes during holiday sales and large drops afterward. They want to avoid over-provisioning hardware and only pay for resources used during peak demand. Which cloud computing benefit directly addresses this need?

Elasticity is the correct answer because it specifically refers to the ability of a cloud system to automatically and dynamically adjust computing resources to meet fluctuating demand. This means resources can scale up during peak times (like holiday sales) and scale down during off-peak times, ensuring the company only pays for what it uses. Scalability is a broader concept referring to the ability to handle increased workload, but elasticity adds the crucial element of automatic, dynamic scaling both up and down. High Availability ensures continuous operation but doesn't directly address cost optimization through dynamic resource adjustment. Disaster Recovery focuses on business continuity after a major outage, not on managing routine traffic fluctuations.