In which sentence is the ellipsis used CORRECTLY?
A) Researchers reported that they are "working . . . devices to assist . . . elderly."
B) Researchers reported that they are "working on new devices to assist the elderly . . ."
C) Researchers reported that they are "working . . . to assist the elderly . . ."
D) Researchers reported that they are "working on . . . devices to assist the elderly."