Suppose we have a Caesar shift cipher that shifts the English alphabet by N places, and a plaintext to apply it to$.$ We then apply the cipher $26$ times $--$ each time to the output of the last time. When we're done, we see that we landed on the plaintext we started with!

Which of the following is true?

Group of answer choices

N could be any number.

N must be even.

N must be odd.

N must be a multiple of $4.$

This can't happen for any value of N$.$