D). Write a function named isPalindrome, that accepts a sentence containing blanks and punctuation and returns true if its a palindrome, false otherwise. HINT: reverseStr from P3 has a role to play here.

E). Write a function named factorial() that accepts a positive integer N and returns N!

F) Write a function nChooseK(), that accepts two positive integers, N and K, and returns the number of ways to arrange K items out of a set of N. You should use factorial() in this function.

G) Write a function factorsOfN(), that accepts a positive integer N, and returns an array containing all of its factors.

H) Write a function isPrime(), that accepts a positive integer and returns true if it is a prime, false otherwise. You should use factorsOfN() in this function.