Context: Blue poison dart frogs 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: blue poison dart frog.
Which animal's skin is better adapted as a warning sign to ward off predators?
A. impala
B. crown-of-thorns sea star
Pick the correct answer from the listed options and provide the letter of the selected option.

B