What is a primary disadvantage of using a private cloud model?

A primary disadvantage of using a private cloud model is the high Capital Expenditure (CapEx) requirements. Building and maintaining a private cloud involves significant upfront investments in hardware, software, data centers, and personnel. While private clouds offer greater control and customization, this comes at a substantial initial cost. High elasticity is incorrect because private clouds can be elastic, but achieving it often requires careful planning and investment, and it's not an inherent disadvantage. Low security is incorrect; private clouds generally offer high security due to dedicated resources and control over the environment. Shared infrastructure is incorrect as private clouds are characterized by dedicated, not shared, infrastructure, which is a feature of public clouds.