The correct answer is (C) Abnormality; a deviation from the general rule; an exception to what is expected; an irregularity, incongruity, inconsistency, abnormality, or peculiarity. A strange or peculiar condition or situation, etc. Something or someone anomalous.

Anomaly comes from Greek anomalia (inequality), Latin anomalia.

Examples of use:

• His very low mark in the December geometry exam was an anomaly.
• Her quiet and reserved nature was an anomaly in an extraverted family.