Correct Option: C

faithful (Adjective) : loyal; true and accurate; not changing anything; staying with or supporting a particular person
treacherous (Adjective) : deceitful ; that cannot be trusted ; intending to harm you ; unfaithful
tactful (Adjective) : diplomatic; careful not to say or do anything that will annoy/upset other people
violent (Adjective) : intense; severe; showing or caused by very strong emotion; very strong and sudden
false (Adjective) : incorrect; wrong; untrue