Choose the best answer. What is one difference between arthropods and echinoderms?

A) Arthropods have exoskeletons, but echinoderms have endoskeletons.
B) Arthropods have jointed legs, but echinoderms have straight legs.
C) Echinoderms have spiny skin, but arthropods have soft bodies.
D) Arthropods have body segments, but echinoderms only have a skeleton

i believe the correct answer from the choices listed above is the first option. the scientists need to look at the   validity of data, claims, hypotheses, and observations before  developing an argument. they base their arguments on facts that are present and they make sure they have proofs. 

explanation:

. the sierra madre fault zone of southern california

. the san andreas fault california

some inherited genetic mutations can be good for the offspring, so the answer is different genetic mutations cause many forms of cancer.