U did not provide the sentence but it found it as shown below: "It is important for us choir members to take individual responsibility for learning our part." Well, assuming that the italicized pronoun is the word 'us' , the answer is : E. it is the objective form of we
Since it acted as an object, it needed to be change into the objective form. 'It is important for we . . .' will not work since we is a subjective pronoun
