Microbes are present everywhere—in soil, water, air, inside our bodies and that of other plants and animals. They
are present even at sites where no other life-form could possibly exist, such as

The correct option is B All of the above

Introduction to extremophiles
Certain bacteria can flourish in extreme climatic conditions, called extremophiles.
For example:-

• Thermophiles: These bacteria flourish at temperatures exceeding ${10}^{\circ }$. They contain enzymes that do not get denatured at high temperatures.
• Psychrophiles: These bacteria are cold-loving, adapting in low temperatures such as $0^{\circ }$ or lower. They contain antifreeze compounds that help them adapt to such temperatures.
• Acidophiles: These bacteria can grow in acidic medium. The optimum pH for their growth is less than 3. They have special membrane modifications, reversed membrane potential, and abundant secondary transporters. All these ensure that protons are being pumped out keeping their cytoplasm near neutral. They are found in discharge from mines.