The best recommendation for an organization that is unable to add new servers on demand in a cost-efficient manner is to build a virtual environment. A virtual environment is a technology that allows multiple virtual machines to run on a single physical server, sharing its resources and capabilities. A virtual environment can help the organization add new servers on demand in a cost-efficient manner by reducing the need for hardware acquisition, maintenance, and power consumption. The other options are not as effective as building a virtual environment, as they do not address the root cause of the problem or provide the same benefits.
Increasing the capacity of existing systems is a short-term solution that can help improve the performance and availability of the current servers, but it does not enable the organization to add new servers on demand in a cost-efficient manner. Upgrading hardware to newer technology is a costly solution that can help enhance the functionality and reliability of the servers, but it does not enable the organization to add new servers on demand in a cost-efficient manner. Hiring temporary contract workers for the IT function is an irrelevant solution that can help supplement the IT staff's skills and knowledge, but it does not enable the organization to add new servers on demand in a cost-efficient manner. References: CISA Review Manual (Digital Version), Chapter 3, Section 3.3.1