PLEASE HELP THIS IS TIMED I'LL GIVE BRAINLIEST!!!!!!
The chart shows characteristics of two groups of mammals.
Mammal Characteristics
Which headings correctly complete the chart?
A. X: Marsupial
Y: Placental
B. X: Placental
Y: Marsupial
C. X: Monotreme
Y: Placental
D. X: Placental
Y: Monotreme