The correct answer is C. Change the letter y to i and add -es.
Step-by-step explanation:
In the English language, singular nouns can become plural nouns in most cases by adding "s" to the noun as in the case of "house" that becomes plural by adding "s" to it as "houses". However, there are exceptions to this rule as some nouns need to be added "-es" rather than only "s" as in "kiss" and "kisses" or even changing part of the word before adding the "s" or "es" to make the noun plural as in "wife" and "wives" or "fly" and "flies". In the case of the singular noun "story", the plural form of it is "stories" and this implies the plural is formed by changing the letter "y" by "i" and then adding "-es". Therefore, the plural spelling rule for the word "story" is to change the letter y to i and add -es.