In which sentence is the underlined phrase an adverb clause?



A beagle puppy in the Florida Everglades was trained to sniff out pythons in the park.


Dolphins, whom scientists say can find things with their own sonar, are trained to find underwater explosives.


Dogs, such as bloodhounds, have a great sense of smell that allows them to help detectives.


Although we might consider animals as pets, many animals work.