One of Erikson's most important contributions to personality theory is his concept of

A) organ inferiority.
B) traits as the building blocks of personality.
C) archetypes of the unconscious.
D) personality development across the lifespan.

Erikson's most important contribution to personality theory is his concept of personality development across the lifespan. He proposed eight stages of psychosocial development, each with a unique challenge or crisis to be resolved in order for the individual to progress to the next stage. This theory emphasizes the importance of social and cultural influences on personality development and highlights the lifelong nature of personality growth and change.