Read the following paragraph carefully and answer the given questions.

Certain types of leukocytes (WBC) of our body like polymorpho-nuclear leukocytes (PMNL-neutrophils) and monocytes and natural killer (type of lymphocytes) in the blood as well as macrophages in tissues can phagocytose and destroy microbes. For determining the cause of allergy, the patient is exposed to or injected with very small doses of possible allergens, and the reactions studied. The use of drugs like anti-histamine, adrenalin and steroids quickly reduce the symptoms of allergy. Heroin, commonly called smack is chemically diacetylmorphine which is a white, odourless, bitter crystalline compound. This is obtained by acetylation of morphine. Techniques like radiography (use of X-rays), CT (computed tomography) and MRI (magnetic resonance imaging) are very useful to detect cancers of the internal organs. Different species of Plasmodium (P. vivax, P. malaria and P. falciparum) are responsible for different types of malaria. Of these, malignant malaria caused by Plasmodium falciparum is the most serious one and can even be fatal.

Heroin, commonly called smack is chemically ______ which is a white, odourless, bitter crystalline compound.

Diacetylmorphine

The correct answer is Option (4) → Diacetylmorphine 

Opioids are the drugs, which bind to specific opioid receptors present in our central nervous system and gastrointestinal tract. Heroin , commonly called smack is chemically diacetylmorphine which is a white, odourless, bitter crystalline compound. This is obtained by acetylation of morphine. Heroin is derived from morphine, which is a naturally occurring alkaloid found in the latex sap of the opium poppy plant, Papaver somniferum. The opium poppy plant has been cultivated for centuries for its medicinal properties. Morphine is a very effective sedative and painkiller, and is very useful in patients who have undergone surgery.