Explanation

Dynamically scale to meet usage demands is the correct answer because it directly addresses the core principles of elasticity and agility in cloud computing.

Key Concepts:

• Elasticity: The ability to automatically scale computing resources up or down based on actual demand
• Agility: The capability to quickly respond to changing business requirements

Why Option B is Correct:

• Allows automatic scaling based on real-time usage patterns
• Eliminates over-provisioning and under-provisioning
• Enables cost optimization by paying only for resources actually consumed
• Supports unpredictable workloads and traffic spikes

Why Other Options are Incorrect:

• Option A: Provisioning based on past usage and theoretical peaks leads to over-provisioning and doesn't leverage cloud elasticity
• Option C: Building in a traditional data center with physical access contradicts cloud principles and doesn't provide the same level of agility
• Option D: While loosely coupled components are a good architectural practice, this specifically addresses modularity rather than elasticity and agility

This best practice enables organizations to optimize costs while maintaining performance and availability, which are fundamental benefits of cloud computing.