Which personnel must attend Waterfront briefs according to the Executive Officer's responsibilities?

The requirement for specific personnel to attend Waterfront briefs is designed to ensure that those responsible for maintenance and management are informed and equipped to handle their duties effectively. The individuals mentioned—Work Center Supervisors (WCS), Leading Chief Petty Officers (LCPO), 3-M Coordinators (3MC), and Senior Maintenance Managers or Officers (SMMO)—play crucial roles in the operational and maintenance aspects of the Navy's systems. Their attendance is critical because they are integral to the implementation and oversight of maintenance practices and policies throughout the command.

These key personnel are tasked with overseeing the readiness, safety, and efficiency of their respective work centers, making it essential for them to be well-versed in the current operational environment and directives delivered during the Waterfront briefs. This targeted approach ensures that the right information is disseminated to those who can act on it, promoting a cohesive and effective maintenance strategy within the fleet.

The other options may suggest broader groups but do not align with the focused nature of the roles that need to be engaged in these briefs, which is why the correct choice centers on the specific responsibilities of the key personnel involved in the maintenance framework.