Context: Fire salamanders have poisonous glands in their brightly colored skin. The bright colors serve as a warning sign that the animal is poisonous. The 's skin is adapted to ward off predators.
Figure: fire salamander.
Which animal's skin is better adapted as a warning sign to ward off predators?
A. blue poison dart frog
B. gray tree frog
Determine the correct option from the provided choices and reply with its corresponding letter.

A