need help on microsoft Access homework for my ms access 2016 class

[NatsuD66]

Hi Everyone,
I'm currently working on some ms access homework and one of the steps requires a validation rule for a specific field that will accept the values 2018, 2019, 2020, and 2021 in this order. I was wondering if anyone knew what the validation rule I need to use because I've researched the heck out of it and can not figure it out. It would be greatly appreciated if someone could help me figure it out.
Thanks again,
NatsuD66

P.S,
I have put the attachment of the instructions so that you guys can physically see what I'm talking about.

[Micron]

It's not making sense to me. It says "...OR 2021 twice and you are saying AND ("...2020, and 2021 in this order."). Since it's not a case of AND, an order doesn't apply since there's only to be one value. Even if you're dealing with a multi-value field (which most of us would never use, but I guess someone feels it's necessary to craft a question for such a thing) it seems that only one value is being asked for.

[Bulzie]

In Input Mask, put #### to restrict values to numeric
In Validation Rule put 2018 Or 2019 Or 2020 Or 2021
In Validation Text put Please enter 2018 Or 2019 Or 2020 Or 2021.

Don't forget the period. Come back and let us know your Grade for the exercise