The correct answer is B. Bacilli.
Bacilli are rod-shaped bacteria. They are the most common type of bacteria and can be found in soil, water, and the air. They can also be found in the human body, where they can cause a variety of diseases, including pneumonia, tuberculosis, and food poisoning.
Cocci are spherical bacteria. They are the second most common type of bacteria and can be found in many different environments, including the human body. Some cocci are harmless, while others can cause diseases such as strep throat and meningitis.
Spirilla are spiral-shaped bacteria. They are less common than cocci and bacilli, but they can still cause diseases, such as Lyme disease and leptospirosis.
None of the above is not the correct answer.