[A]: Dental formula is the number of teeth in upper jaws of one side and low jaw of same side
[B]: This can be used for non mammalian and insectivorous mammals also.
A. If both A and R 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 and R is false
D. If both A and R are false