An apostrophe is a punctuation mark that is used to show possession. It is used to highlight the possessive case of the nouns in the sentence. With the singular noun, it is used before the letter 's'. With the plural nouns, it is used after the letter 's'. From the given phrases, the correct phrase is 'the women's association'. The word 'women' is the plural noun. The letter 's' is used after the apostrophe.
