This scenario describes vendor lock-in, which occurs when an organization becomes highly dependent on a specific cloud provider’s proprietary services, architectures, APIs, or managed features, making migration to another provider difficult, costly, or technically impractical. In the CompTIA Cloud+ (CV0-004) objectives related to cloud design, risk management, and interoperability, vendor lock-in is a known risk that can impact long-term cost control, flexibility, and negotiating power. When applications are built around provider-specific components (such as proprietary databases, messaging services, identity integrations, serverless runtimes, or monitoring tools), moving to another provider often requires major redesign, refactoring, or data transformation—far beyond a simple “lift and shift.”
Option A (PaaS) is a service model and may contribute to lock-in, but it is not the situation described. Option B (oversubscription) refers to allocating more virtual resources than physically available. Option D (regulatory compliance) relates to meeting legal/industry requirements. Because the key issue is that reliance on provider-specific features prevents feasible migration, vendor lock-in is the best answer.