Zero-day exploits are considered the most dangerous mobile attack vector in CEH v13 Mobile Platform Hacking. These exploits abuse previously unknown vulnerabilities, meaning no patches, signatures, or defenses exist at the time of attack.
In healthcare environments, mobile devices access sensitive EHR systems and operate under strict compliance requirements. Zero-day exploits can bypass mobile OS security, sandboxing, and antivirus controls entirely.
App spoofing and Bluejacking are easier to detect and mitigate through user awareness and Bluetooth controls. Side-channel attacks are highly specialized and rare in enterprise mobile environments.
CEH v13 stresses that zero-day attacks pose the greatest risk due to lack of detection mechanisms, making Option A correct.