Identify each of the following definitions as a synonym definition, class definition, or definition by negation. Select the correct answer. Lou Gehrig's disease is a progressive, terminal illness characterized by deterioration of the nerve cells that control voluntary muscle movement.

A) synonym definition
B) class definition
C) definition by negation

Lou Gehrig's Disease

Also known as Amyotrophic Lateral Sclerosis (ALS), a progressive neurodegenerative disease affecting nerve cells in the brain and spinal cord.

Terminal Illness

A disease or condition that is ultimately fatal and has no available cure.

Voluntary Muscle Movement

Movement that is controlled consciously by the brain, involving muscles that can be moved deliberately such as those in the arms and legs.