The writer is considering changing sentence 4 (reproduced below) so that it clearly articulates the passage's overarching claim. By studying this new dinosaur, paleontologists believe they can determine the precise function of its mysteriously heart-shaped tail bones. Which of the following versions of the underlined portion of sentence 4 best supports this goal?
Answer A: (as it is now) B solve the mystery of how titanosaurs became so widespread during the Cretaceous period
Answer B: solve the mystery of how titanosaurs became so widespread during the Cretaceous period C develop more effective techniques for extracting fossils from rugged terrain
Answer C: develop more effective techniques for extracting fossils from rugged terrain D learn how titanosaurs used their immense size to defend themselves from predators such as the Tyrannosaurus rex
Answer D: learn how titanosaurs used their immense size to defend themselves from predators such as the Tyrannosaurus rex predict with greater accuracy where to find other titanosaur fossils in Africa