What does the word "advanced" (Sentence 2, Para.4) refer to
A) Improved. C) Progressed.
B) Getting old. D) Complex.

A．When a general practitioner is available to perform it.
B．When there is room in the hospital emergency ward for the patient.
C．When the patient can be expected to show favorable results.
D．When the doctor recommends against it.

A．An operation to bypass the heart.
B．An operation to replace a disabled artery with another artery.
C．An operation to construct a passage around a blocked artery.
D．An operation to take care of faulty heart action.