In the palindrome checking function, which condition leads to the function returning false?

• A. The loop finishes without finding any mismatch.
• B. The string is empty.
• C. s[left] != s[right] is encountered during the loop.
• D. The loop increments both indices regardless of content.

Answer: (C)

Two-pointer palindrome checks rely on matching characters from opposite ends. If you ever encounter a pair that doesn’t match, you can conclude the string isn’t a palindrome and return false. That exact moment corresponds to s[left] != s[right] inside the loop.

If the loop finishes with all mirrored pairs equal, the string is a palindrome and you would return true. An empty string is typically treated as a palindrome, so it would not cause a false. Incrementing both indices regardless of content would bypass the needed comparisons and could lead to incorrect results, but the decisive trigger for returning false is finding a mismatched pair.