Mandatory directives are

• A. Verbal reminders from field employees
• B. Only authorities
• C. Written, printed, or displayed authorities or speed restrictions issued by the train dispatcher or control operator.
• D. Only speed restrictions

Answer: (C)

Mandatory directives are authoritative instructions that train crews must follow, issued by the train dispatcher or control operator. They can be in written, printed, or displayed form and include both authorities to move or occupy a track and any speed restrictions. This makes the option that describes them as written, printed, or displayed authorities or speed restrictions issued by the dispatcher or control operator the best fit, because it covers both the source of the directive and the ways it can be conveyed. Verbal reminders from field employees don’t carry the formal dispatcher-issued authority, and focusing only on speed restrictions misses the broader range of directives that control movement.