a) Write a recursive Java method that will accept a positive integer as an argument, returning the product of the digits in that integer.

b) Write a recursive Java method that will accept two positive integers as arguments, returning the product of those two integers.

c) Write a recursive Java method that will accept a string as an argument, returning whether that string is a palindrome. Recall, a palindrome is a sting of characters that reads the same forwards or backwards (i.e. abba, 12321).