Sentence Correction

Prompted by recent discoveries, paleontologists have started research on the fossils of feathered dinosaurs, a study that, igniting the debate over when and why dinosaurs developed plumage, and that makes many researchers believe that possibly all or most of them had feathers.

A) research on the fossils of feathered dinosaurs, a study that, igniting the debate over when and why dinosaurs developed plumage, and that makes
B) research on the fossils of feathered dinosaurs, a study that has ignited the debate over when and why dinosaurs developed plumage and that makes
C) researching the fossils of feathered dinosaurs, a study igniting the debate over when and why dinosaurs developed plumage, and made
D) research on the fossils of feathered dinosaurs, the study has ignited the debate over when and why dinosaurs developed plumage, making
E) researching the fossils of feathered dinosaurs, igniting the debate over when and why dinosaurs developed plumage, and the study makes

Source- e-gmat

Can you please explain why option D is wrong and why option B is right?

Hello!

Answer D is incorrect because it has a comma splice here (shown in bold):
research on the fossils of feathered dinosaurs, the study has ignited the debate over when and why dinosaurs developed plumage, making

When connecting two complete sentences, one must use a semicolon (;), and semicolon and a transition phrase (;furthermore,), or a comma with a conjunction (,so).

B is correct because the phrase after the comma cannot stand alone as a complete sentence the way it's written, so it's okay to connect the two with just a comma.

I hope that helps. I'm available if you'd like any follow up.