Answer: the word womens'
Step-by-step explanation:
We use the possessive form -s to express belonging. In the text given the writer wants to convey a sense of belonging between sandals and sunglasses and women.
The rules of possessive -s state that in order to make the possessive form we add 's at the end of the noun except in the case of plural noun that end in S in which we just add the apostrophe. The word women is a plural noun but it does not end in S, so, if we want to make it possessive we have to add 's.
Instead of WOMENS' it should be WOMEN'S