Choose the One Most Appropriate Letter for Each

Choose the one most appropriate letter for each.
-placoderms

A) cartilaginous skeleton; jaws
B) reptile with four-chambered heart
C) separate openings for the urinary, reproductive, and excretory systems
D) legless amphibian
E) invertebrate chordate; no metamorphosis
F) endotherm with feathers
G) limbless reptile
H) most primitive fishes with jaws; extinct
I) modern-day parasitic jawless vertebrate
J) North America's only native marsupial
K) adults are barrel-shaped and secretes a covering of polysaccharides
L) egg-laying mammal
M) swim bladder for buoyancy
N) larvae typically have gills and develop lungs as they mature