______ is problematic to define and has a number of official and legal definitions.

A) Murder
B) Rape
C) Terrorism
D) Treason

Terrorism is the only option among the given choices that is known to have multiple official and legal definitions, making it difficult to define accurately. The definition of terrorism can vary depending on the context, cultural and political factors, and legal frameworks in different countries. Terms like "terrorist," "terrorism," and "terrorist act" have been defined differently by various international bodies, governments, and legal scholars, often with controversial implications. The lack of consensus on the definition of terrorism has also hindered global efforts to combat and prevent acts of terrorism.