A functional region might be created by all of the following except A) a public transportation system
B) the broadcast area of a local television station
C) the influence of an elected official
D) the spread of an infectious disease
E) the customer base of a particular business

The spread of an infectious disease can not create a functional region.

A functional region refers to a geographical area which is centered around specific focal point with a specific function.

An example of functional region includes

So, a functional region might be created by

Therefore, the Option D is correct because the spread of an infectious disease can not create a functional region.

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i think the answer is going to be arabian desert!