Answer: Choice D 
Reason:
Exponential functions have the variable in the exponent.
Choice A is a polynomial, which means we can rule it out. Choice B is a log function, so we can rule it out also.
Choice C is a rational function because it is a ratio of two polynomials. This rules out choice C.
Choice D is the only function with the variable in the exponent. That is assuming you meant to say
instead of 
Answer: <u><em>The building is 35 meters tall.</em></u>
Step-by-step explanation:
<em>420 </em><u><em>divided by </em></u><em>24 is 17.5 </em>
<em>17.5 </em><u><em>x </em></u><em>2 is 35 </em>
<em>(im multiplying by two because it says that a person who is 2 meters tall casts a shadow that is 24 meters long. ***)</em>
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Answer: is it B?
Step-by-step explanation: