What characteristic of donatello’s work to define him?

Though Donatello was a descendant of a branch of the important Bardi family, he was brought up in a more plebeian tradition than his older contemporary Lorenzo Ghiberti. Gifted with humanistic insight and a quality of will that were highly prized in the early Renaissance, Donatello revealed the inner life of his heroic subjects, memorable images which have conditioned our very conception of 15th-century Florence. Sharing neither Ghiberti's feeling for line nor Filippo Brunelleschi's interest in proportion, Donatello worked creatively with bronze, stone, and wood, impatient with surface refinements and anxious to explore the optical qualities he observed in the world about him. His later art, saturated with the spirit of Roman antiquity, is frequently disturbing in its immediacy as it attains a level of dramatic force hitherto unknown in Italian sculpture.

Answer ( a ) both roland and clive are correct