Step 1: Map Freud’s structural model.
{Id} seeks immediate gratification (pleasure principle); {ego} mediates with reality (reality principle); {superego} internalizes moral standards.
Step 2: Identify the “morality principle.”
The superego judges actions against ideals (conscience/ego-ideal), producing pride or guilt; hence it embodies the morality principle.
Step 3: Eliminate distractors.
“Unconscious” is a level of mind, not an agency; the {ego} is pragmatic, not moralistic.
Step 4: Conclude.
\[
\boxed{\text{Superego (Option C).}}
\]