A retailer wants capacity to grow AND shrink automatically in response to real-time demand, so they never pay for idle resources. Which cloud capability is this?
A.Scalability
Scalability means the system can grow, but doesn't imply automatic scale-in/scale-out.
B.Elasticity
Elasticity = automatic, demand-matched scaling in both directions. Correct.
C.High availability
High availability is about uptime, not capacity adjustment.
D.Predictability
Predictability refers to consistent performance/cost forecasting.
Why this answer
Elasticity is the automatic, demand-driven expansion AND contraction of resources. Scalability is the broader ability to grow capacity (which may be manual). The exam keyword pair is 'automatic' + 'shrink' → elasticity.
Correct answer: B · Last reviewed 2026-02-13
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