Tranquilizers are a class of chemical compounds used for the treatment of stress and mild or even severe mental diseases. For example, noradrenaline is one of the neurotransmitters that play a role in mood changes. If the level of noradrenaline is low for some reason, then the signal-sending activity becomes low, and the person suffers from depression. In such situations, antidepressant drugs are required.

Aspirin inhibits the synthesis of chemicals known as prostaglandins which stimulate inflammation in the tissue and cause pain. These drugs are effective in relieving skeletal pain such as that due to arthritis. These drugs have many other effects such as reducing fever (antipyretic) and preventing platelet coagulation. Because of its anti-blood clotting action, aspirin finds use in the prevention of heart attacks.

Antibiotics are used as drugs to treat infections because of their low toxicity for humans and animals. Paul Ehrlich, a German bacteriologist, investigated arsenic-based structures in order to produce less toxic substances for the treatment of syphilis. He developed the medicine, arsphenamine, known as salvarsan.

Antiseptics are applied to the living tissues such as wounds, cuts, ulcers and diseased skin surfaces. Examples are furacine, soframicine, etc.

So, the correct matching is A-III, B-I, C-II, D-IV.