Answer:
D. Barn owls move silently through the night. Scientists have conducted experiments demonstrating that barn owls are able to hunt in complete darkness using only their hearing to guide them. In fact, barn owls can pinpoint the exact location of prey moving through the grass beneath them.
Step-by-step explanation:
Option D is the best that revises the paragraph to convey the same meaning while maintaining a formal tone throughout.
From the main paragraph, it was stated that some people who study animals and these are actually scientists. This then means that Option D still maintained and conveyed the same message.
Option A isn't correct because the tone wasn't formal enough. Option B didn't actually convey the exact message the paragraph conveyed. While Option C didn't also pass an accurate information as the main paragraph. It just stated "people" whereas the main paragraph stated "some people who study animals..."
Option D is the correct answer.