Which phase of the CEH framework involves identifying active hosts and open ports?

The correct choice focuses on the scanning phase of the CEH framework, which is primarily concerned with actively probing a network to discover live hosts and identify open ports. During this phase, tools are employed to send packets to various IP addresses to see which ones respond, indicating that those hosts are active.

Moreover, scanning involves further probing of the active hosts to determine which ports are open and what services are running on those ports. This is critical for understanding the attack surface of the target environment and helps in assessing the potential vulnerabilities that may be exploited during later phases of ethical hacking.

In contrast, the reconnaissance phase is more about gathering information in a passive manner, such as using publicly available data and other non-intrusive means to gather information about the target. The gaining access phase is where the ethical hacker attempts to exploit identified vulnerabilities to gain unauthorized access to systems, and the maintaining access phase involves actions taken to ensure continued control over the compromised systems. Thus, targeting active hosts and open ports is distinctly a part of the scanning phase, making it the most accurate answer.