In comparing the structures of the nervous system in a crayfish and a rat, the following comparison is incorrect: Options: a. Crayfish have a simpler nervous system than rats, with fewer ganglia. b. Rats have a more complex brain with distinct regions for higher cognitive functions compared to crayfish. c. Crayfish rely primarily on sensory organs located on their appendages for perception, while rats have well-developed sensory organs in their head region. d. The nerve fibers in crayfish are unmyelinated, while in rats, many nerve fibers are myelinated for faster transmission of signals.