What is an example of a functional organizational structure?

a spa organized by divisions such as hair, nails, massage, etc.
a hospital organized by divisions such as pediatrics, inpatient, outpatient, etc.
a business with a ceo at the top and divisions below that are arranged by product
a business with a president at the top and departments below that perform various functions

is a correct example of functional organizational structure.

Explanation:

A Functional Organizational Structure can be defined as a skeleton in which workers are organized in such a way that they form groups or sub-parts of organization by making their respective skills the basis for division. Each department with it role from President to Service man will vertically structure to form an Organization. Special units are created that report to the management.

So from given options, a hospital is a best example so far for a Functional Organizational Organization.