The word "malignant" in line 7, paragraph 2 could best be replaced by ______.

A．to persuade people to use the X-ray and the microscope
B．to keep people aware of the principal tools of the physician
C．to advise people to have a routine physical checkup
D．to describe the development of medicine

A．The physician has been able to make wonders alone in the world of medicine.
B．The cooperation between research workers in medicine and in the related sciences will bring about a "golden age of healing".
C．The X-ray and the microscope have been of little help in uncovering truth.
D．Medical workers fully understand electrical body measurements.