Read the passage and answer the following.

Microbes are organisms that cannot be seen with the naked eye. They include bacteria, archaea, protists, viruses, prions, and fungi. They account for most of the diversity of life on earth. Far more microbes inhabit a single person's body than there are people on the entire planet. Microbes also dominate in terms of their ability to live and thrive in extreme environments, including clouds, deep-sea volcanoes, springs, ice caps, and animal intestines. Most animals, including humans, exhibit numerous associations with microbes. Our "human microbiome" includes our skin, hair, mouth, and gut.

Select the chemical substances which are produced by some microbes and they can kill or prevent growth of other microbes :

Antibiotics

The correct answer is Option (2) → Antibiotics

Antibiotics produced by microbes are regarded as one of the most significant discoveries of the twentieth century and have greatly contributed towards the welfare of the human society. Antibiotics are chemical substances, which are produced by some microbes and can kill or retard the growth of other (disease-causing) microbes. Penicillin was the first antibiotic produced by Penicillium notatum.

Penicillin was discovered by Alexander Fleming in 1928. Fleming observed that a certain mold, Penicillium notatum, produced a substance that inhibited the growth of bacteria. This substance, later identified as penicillin, was found to be effective in treating bacterial infections. This antibiotic was extensively used to treat American soldiers wounded in World War II. Fleming, Chain and Florey were awarded the Nobel Prize in 1945, for this discovery. Antibiotics have greatly improved our capacity to treat deadly diseases such as plague, whooping cough (kali khansi ), diphtheria (gal ghotu) and leprosy (kusht rog), which used to kill millions all over the globe. Today, we cannot imagine a world without antibiotics.