Final answer:
Aristotle's Unmoved Mover is characterized as eternal, immovable, and non-material, acting as the first cause in the universe without undergoing any change.
Step-by-step explanation:
Aristotle attributed several key characteristics to the Unmoved Mover, a central concept in his philosophical system. Among them, we can identify three principal attributes: the Unmoved Mover is B. Eternal, C. Immovable, and explicitly not material, hence it lacks D. Material characteristics. Due to its role as the first cause or prime mover, the Unmoved Mover sets all other beings and things into motion without being moved and gives rise to change without changing. According to Aristotle, this entity is the first cause behind all the motion and change we witness in the universe, yet it remains immutable and eternal.