Final answer:
Therizinosaurs, despite being theropods, were herbivorous dinosaurs. They had adaptations suitable for a vegetation-based diet, including a long neck and clawed fingers for reaching vegetation.
Step-by-step explanation:
Therizinosaurs, also known as segnosaurs, were indeed types of theropod dinosaurs, but they were an exception to the rule of theropods primarily being carnivorous. Therizinosaurs are known to have been herbivorous dinosaurs, thus the correct answer to your question is c) Plants.
These dinosaurs had elongated necks and often stood bipedal, using their elongated, clawed fingers to reach for vegetation. Not all theropods, which typically have features associated with a carnivorous lifestyle like sharp teeth and claws, were meat-eaters.
Fossil evidence, including dental structures and the form of the body, suggest that therizinosaurs were adapted for a vegetation-based diet. Also, their relatives, Ornithischia dinosaurs, were all herbivores. Therefore, even though therizinosaurs were theropods, they had a different diet from the majority of the group.
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