Given the task definition and input, reply with output. In this task, you are given two facts, and a multiple-choice question. Based on the given facts, answer the question with index of the correct option (e.g, "A").

Fact1: Adult echinoderms have radial symmetry., Fact2: Animals with radial symmetry lack an anterior and posterior end., Question: Which of the following does not have an anterior and posterior end? (A) Adult mammals (B) Adult reptiles (C) Adult birds (D) Adult echinoderms (E) Earth orbiting the Sun (F) an erupting volcano (G) peachleaf willow (H) sensory neurons
D