To change the sentence, making it more comprehensive, it is possible to rewrite it as follows:
Paleontologists believe they will determine the function of the dinosaur's tail bones through this study.
We can arrive at these answers because:
Unfortunately, you didn't show the part of the sentence that is underlined, and you don't show the answer options. This prevents me from being able to answer the question specifically, but I hope the information above will help you.
More information on how to rewrite a sentence at the link:
https://brainly.com/question/5032491