Question $3$: $(13$ pts$]$ Using the black$-$box testing and in particular the equivalence partitioning method, we want to derive test cases for a program P that verifies the validity of a birthday of a CIT student $($day$,$ month, year$)$ given as input. The output of this program shall be one the two following messages: "VALID" or "NOT$-$VALID" A date is valid if the day, the month and the year are valid. A valid day would be $>=1$ and $<=30,$ and senttimes $31$ A valid month would b e $>=1$ and $<=12.$ A valid year would be $>=2000$ and $<=2024.$ a$)$ What are the equivalence classes of each input of the program P$?[$