The correct answer is B. Molly and Harriet's house
Explanation:
The apostrophe (') is a punctuation mark that is used in the English language in contraction or words or for showing possession. In the case of possession, the apostrophe is used by adding it at the end of a word along with an "s" to show something belongs to someone, for example, the sentence "the book of Paul" can be rewritten as "Paul's book" to use the apostrophe. Besides this, if the noun already ends in "s" there is no need to add another s but just use the apostrophe and in the case of two or more people the apostrophe needs to be used individually if the object or idea is owned individually or using the apostrophe at the end of the people mentioned if the object is owned by all.
Considering this, in the case of the sentence "The house of Molly and Harriet" the correct way to rewrite this sentence by using the apostrophe is "Molly and Harriet's house" considering the house belongs to both of them and therefore the apostrophe should only be used at the end of the names, also as "Harriet" does not end in "s" an "s" should be added after the apostrophe.
