Question

a dog is walking outside and smells something in the grass. after it picks up the smell, the dog suddenly becomes hyper, as well as very aggressive with another dog walking by, which is unusual behavior for this particular dog. what could the dog have detected in the grass that made it unusually hyper and aggressive? neurotransmitters pheromones steroids hormones

Explanation:

Pheromones are chemical signals that can affect an animal's behavior. Dogs have a highly - sensitive sense of smell and can detect pheromones which might cause changes like hyperactivity and aggression. Neurotransmitters are within the dog's body and not something detected externally in the grass. Steroids are a type of chemical compound and not typically something a dog would detect in the grass to cause such a behavior change. Hormones are also internal and not usually detected in the grass to trigger this kind of response.

Answer:

B. pheromones