Unlike other arachnids, which have their nerve cells evenly distributed along their bodies, the scorpion's nerve cells are clustered in its head, like a mammal's.

(A) bodies, the scorpion's nerve cells are clustered in its head, like a mammal's
(B) bodies, the scorpion's head has a cluster of nerve cells, as a mammal does
(C) body, the scorpion has a cluster of nerve cells in its head, as a mammal does
(D) body, nerve cells are clustered in the scorpion's head, like a mammal's
(E) body, a cluster of nerve cells is in the scorpion's head, like a mammal's

Q/A-c why not a