(A) Nowadays there are many self-tutorials available on the internet on how to take care of pets.
This could explain increased awareness, as pet owners might have learned from these tutorials that chocolate is toxic to dogs. This supports the conclusion.
(B) Most breeds of dogs are allergic to chocolate and other products that contain cocoa extracts from which chocolate is made.
This is just a restatement of why chocolate is bad for dogs, not an explanation for why cases have decreased. It doesn’t support the conclusion about increased awareness.
(C) Any treatment provided to pets to address a disease or a condition requires expert medical intervention that cannot be provided at home.
This is irrelevant to why cases of chocolate toxicity have decreased. It doesn’t address awareness.
(D) The number of veterinary clinics in Pupper Town has not reduced significantly over the past three years.
This rules out the possibility that the decrease in cases is due to fewer clinics (which could make it harder to report or treat cases). This indirectly supports the idea that the decrease is due to increased awareness, but it’s not as direct as (A).
(E) The number of pets in Pupper Town has not gone up significantly over the past three years.
This rules out the possibility that the decrease in cases is due to fewer pets overall. This also indirectly supports the awareness explanation, but like (D), it’s not as strong as (A).
The best choice is (A), as it directly provides a reason for increased awareness (availability of self-tutorials), which explains the decrease in cases.
Final Answer:
(A) nowadays there are many self-tutorials available on the internet on how to take care of pets