Which activities are prohibited under Rule G concerning drugs and alcohol?

Rule G specifically addresses the safety and operational integrity of railway operations with strict prohibitions concerning drugs and alcohol. The correct choice encompasses the essential regulation that prohibits personnel from using or being under the influence of alcoholic beverages while on duty. This restriction is in place to ensure that all employees are fit for duty, which is crucial for maintaining a safe working environment and protecting the lives of workers and the public.

Being under the influence of alcohol compromises judgment, reaction time, and overall performance, which can lead to accidents and dangerously unsafe situations. Thus, adhering to this rule is essential for anyone in the rail industry to ensure reliability and safety during operations.

In contrast, the other activities listed do not align with the key prohibitions set forth by Rule G in the same way. For example, consuming caffeine is generally considered acceptable in moderation and does not impair the ability to perform duties. Additionally, the use of controlled substances while off duty isn't specifically addressed in the context of affecting one's on-duty performance under Rule G, while legal recreational drugs may vary in their effects depending on jurisdiction and specific regulations.