Assertion: The duck-billed platypus and the spiny anteater, both are egg-laying animals yet they are grouped under mammals.
Reason: Both of them have seven cervical vertebrae and 12 pairs of cranial nerves.
A. If both A and B are true and R is the correct explanation of A
B. If both A and R are true but R is not the correct explanation of A
C. If A is true but R is false
D. If both A and R are false