The most probable and most likely answer to this problem would be C. revealed much about their behavior.
Out of the four options presented in this problem, C. would only need a complete subject to make it a correct sentence. Options A. by closely watching and gathering data and B. to terrifying effect would probably need other more words and/or phrases to make them more complete. D. insect studies, on the other hand, can also be considered as a correct option IF insect become the subject.
16-17 antonyms 18-19 synonym 20 antonyms
If you are trying to shorten that, it can be written like this; "My parents and the vet told me about different types of dogs."
