The correct answer is B. A religious group assassinates a politician for demanding more separation of church and state.
Explanation
Terrorism is a form of action of a specific group that is characterized by using violence and terror to cause remembrance in the population and make a specific demand. In general, terrorist actions use systematic violence to defend their ideologies and attack anyone who is considered to be a violator or opponent of it (it can be the government, a minority group, or another). According to the above, the correct answer is B. A religious group assassinates a politician for demanding more separation of church and state because it is a violent act in response to an action that goes against the ideology of the religious group.
The US was isolationist, since they believed neutrality would allow them to avoid being involved in the war. Woodrow Wilson in particular was a proponent of this policy.