How is internal radioactive material typically eliminated from the body?

The elimination of internal radioactive material from the body primarily occurs through biological processes or radioactive decay, making this the most accurate choice. Biological processes refer to the body's natural mechanisms for metabolizing and excreting substances, including radioactive materials. This may include excretion via urine or feces, where the body gradually processes and eliminates contaminants.

Radioactive decay plays a role as well, as unstable isotopes undergo transformations, potentially resulting in different isotopes that are less harmful or that the body can eliminate more easily. Through natural metabolic pathways, the body can enhance the breakdown and removal of these materials over time.

The other options do not accurately represent the typical elimination processes. Surgical extraction is an invasive procedure and not a standard method for removing internal radioactive material. Chemical neutralization may occur in some contexts, but it is not a reliable method for handling internal contamination with radioactive materials. Increased hydration can aid in the elimination of some substances but is not specific to radioactive materials and is not a standalone method for their removal.