Final answer:
The chisel-shaped teeth of Heterodontosaurus are indicative of a d) plant-eating diet, as herbivorous animals, have teeth specialized for grinding tough plant materials.
Step-by-step explanation:
The chisel-shaped teeth of Heterodontosaurus suggest it was a plant-eater. This deduction is based on the observation that herbivores have teeth specialized for grinding food, which includes tough plant material. In contrast, carnivores possess more teeth that are specialized for ripping food apart. The distinct chisel shape of Heterodontosaurus teeth would be effective for shredding plant material, which is consistent with characteristics found in other herbivorous species. Additionally, the presence of heterodont teeth, which are different types of teeth modified for different purposes, supports the idea that Heterodontosaurus had a varied diet primarily consisting of plant matter but may also have been capable of processing other types of food if necessary.