iteratively.

Question $3(2$ points$)$

A word$-$unit palindrome is a sentence that produces the same words forward or backward. For example, 'Please me by standing by me please' is a word$-$unit palindrome. Suppose you wish to implement a recursive function that can check sentences to see if they are word$-$unit palindromes. Which answer below could be a base case?

Words that are the same forward and backward

Words that have only one letter

Sentences that have only one word

Sentences that produce the same words forward or backward