The federal government requires hospitals to tell a Medicare patient of their legal right of challenge their discharge if they feel they are being sent home prematurely.
(A) hospitals to tell a Medicare patient of their
(B) hospital to tell Medicare patients that they have a
(C) hospitals to tell Medicare patients that there is a
(D) that hospitals tell a Medicare patient of their
(E) that hospitals tell a Medicare patient that they have a

doubt: is the non underlined portion "of challenge their discharge" not wrongly written? i feel that it should be "of challenging their discharge"