The right option is; B.) A dog walks to a stream and drinks when it gets thirsty
“A dog walks to a stream and drinks when it gets thirsty” does not describe a structural adaptation. Structural adaptations are physical features of an organism (plants and animals) that help them to survive and thrive in their environment. Structural adaptations can influence organisms on how they reproduce, protects themselves, or how they move. Structural adaptations include the fur on a bear, the long trunk of an elephant, the bill on a bird, the thorns or a rose bush.