B) ethical practice of medicine
the Hippocratic Oath (named after Hippocrates, the father of modern medicine) entails things such as treating a patient as a whole, not just as the illness, not playing at God while treating a patient, etc.

We can see an object only when light from an object enters our eyes. The light may have been emitted by the object or may have been reflected by the object. A mirror changes the direction of light that falls on it. Actually a narrow beam of light is made of several rays.