What is the correct possessive form of dish? dish’s dishes’ dishes dishs’?

Possessive form is shown by adding an apostrophe and an s.
It represents something that belongs to something/someone.

Looking at the answer choices...
a.) dish's
b.) dishes'
c.) dishes
d.) dishs'

I believe answer choice a.) is correct.
b.) is for multiple dishes, but we want the singular form.
c.) doesn't even have an apostrophe. It's just plural of dish.
d.) is plural (and spelled wrong) and possessive, but, again, we just want singular