Often you may hear in the news the term "disenfranchisement", which means "taking away someone's right to vote". Another term for this is "voter suppression" or "voter disqualification". There may be valid reasons to do this such as the person has committed a crime and it is against the law for people of this nature to vote; though many would argue that this is unconstitutional.
Side note: The answer choice C is close, but voting is not an obligation. It's a choice.
