Answer:
IMO it's probably option A
The sentence that would best fit at the beginning of a first paragraph and would also make the best topic sentence is: Mammoth hot springs is a popular attraction because the springs are unique. The correct answer would be option D. This sentence is the correct answer because it is the only sentence that introduces the topic.
we know that
The word odometer derives from the Greek hodós, which means "trajectory", "way" or "measure". An odometer is a device used to measure the distance traveled by a car. The result of this measurement appears on the instrument panel of your car and can be mechanical or digital.
see the attached figure to better understand the question
therefore
the answer is the option
A. total number of miles your car has been driven