What is required under Modified Zebra conditions?

Under Modified Zebra conditions, setting Material Condition Yoke is essential. This condition serves as an intermediate level of readiness between full battle conditions and less restrictive conditions. Material Condition Yoke entails specific measures to secure certain areas of the ship while allowing for operational flexibility. It emphasizes maintaining watertight integrity, ensuring that doors and hatches are closed as necessary, while still permitting some movement and access for personnel within the ship.

In contrast, the other choices do not align with the requirements of Modified Zebra conditions. While relaxation of security measures may seem plausible in certain operational contexts, Modified Zebra is specifically designed to heighten vigilance without compromising essential safety. Opening all watertight doors and hatches would compromise the vessel's integrity during potential emergencies, and allowing unrestricted access for inspections defeats the purpose of maintaining readiness and securing critical areas. Thus, the focus on setting Material Condition Yoke represents a balanced approach to maintaining safety and operational readiness under these circumstances.