Which population is most at risk for severe outcomes from iodine deficiency?

People who drink fluoridated water, since fluoride completely blocks iodide transport into the thyroid in everyone.

Individuals who exclusively consume iodized salt, as they always develop goiter due to excess iodine deposits.

Healthy young adults who eat a varied diet, because they are least able to store iodine and suffer immediate neurologic decline.

Fetuses and infants (due to risk of congenital hypothyroidism causing stunted growth and impaired brain development).