What case in Latin would the word sister's be in the folllowing sentence? The sister's jacket was on the floor. PLZ HELP latin

The answer isharmonia which was written by rythem. 

Translation: we have as many pens as they.if this question is asking whether the grammar is correct, or incorrect, then the answer should be: incorrect.  a sentence with better grammar would be: we have as many pens as them.or in spanish: tenemos tantos corrales como ellos.hope this ! : )

The answer is d to the question