Ellen is 87 years old and has been admitted to the hospital for pneumonia. Her attending physician has confirmed that she can not understand and appreciate health care decisions. Assuming that Ellen has no advance directive and that all of the following are now reasonably available, who is now authorized to make health care decisions on Ellen's behalf?

A. The agent designated in Ellen's health care power of attorney

B. Ellen's husband (from whom she is not divorced, but with whom she fights)

C. Ellen's sister

D. Ellen's oldest child

E. None of the above