Which of the following homework problems requires a conditional loop?

Question $4$ options:

Write a program that lets the user enter a nonnegative integer and then uses a loop to calculate the factorial of that number.$$

Write a program with a loop that displays the projected semester tuition amount for the next $5$ years.

Compute the average of the numbers from $1$ to n $($where n is a positive integer value$)$ and assign it to the variable avg.

Write a loop that reads strings from standard input where the string is either "land", "air", or "water". The loop terminates when $"$xxxxx$"($five x characters$)$ is read in$.$