Which phenomenon includes criminal acts aimed at generating terror or political change at sea?

The correct choice is terrorism because it specifically refers to criminal acts intended to instill fear or make a political statement. Terrorism at sea can take various forms, including attacks on ships, maritime infrastructure, or specific maritime stakeholders, all with the objective of achieving political goals through fear. This is distinct from other terms such as sabotage, which typically refers to acts aimed at damaging property or disrupting operations without the broader political agenda, or piracy, which primarily involves robbery at sea for personal gain rather than a political motive. Economies of scale, on the other hand, pertains to the cost advantages that enterprises obtain due to their scale of operation, which does not relate to criminal acts or political change. Therefore, terrorism is the most fitting term for acts aimed at generating terror or political change at sea.