What does the root 'ather/o' refer to?

The root 'ather/o' specifically refers to fatty plaque, particularly in the context of atherosclerosis, where the accumulation of fatty substances, cholesterol, and other cellular debris builds up within the arterial walls. This buildup can lead to the narrowing and hardening of arteries, significantly contributing to cardiovascular diseases. Understanding this root is crucial for interpreting related medical terms, such as atheroma (a tumor or growth of fatty plaque in the arteries) and atherosclerotic (pertaining to the condition characterized by plaque buildup). The other options pertain to different medical roots or conditions and do not relate to the concept of fatty plaque.