The root "lith/o" refers to which of the following?

The root "lith/o" comes from the Greek word "lithos," which means "stone." In medical terminology, it is commonly used to describe conditions, procedures, or substances related to stones, particularly in reference to the urinary or biliary systems. For example, terms like "lithiasis" refer to the formation of stones within the body. Understanding this root helps in comprehending various medical conditions associated with stones, such as kidney stones or gallstones.

The other roots provided in the choices relate to different concepts: "lobe" refers to a section or division (often used in anatomy to describe parts of the brain or lungs); "fat" pertains to the adipose tissue in the body; and "loin" is associated with the lower back area, typically in the context of anatomy or pain. However, in the context of the question, "stone" is the correct interpretation of the root "lith/o."