Answer: C) unicellular Explanation: An organism is a living thing, and there are two broad categories of organisms: those made up of only a single cell, and those made up of multiple cells. Single-celled organisms means which contains only one cell are called unicellular organisms. 'Uni-' means 'one,' so the name 'unicellular' literally means 'one cell.'   Examples of Unicellular or Single celled organisms ::   Prokaryotic organisms like Bacteria,... Some algae like green algae, euglena,...

All of these diseases are caused by bacteria i.e. Pneumonia, Cholera, Tuberculosis. Cancer is caused by uncontrolled cell division. Pneumonia is caused by a bacterium Streptococcus pneumoniae. Cholera is caused by a bacterium Vibrio cholerae.

Penicillin is obtained from fungi, specifically a group of molds known as Penicillium. The discovery of penicillin, one of the first widely used antibiotics, is credited to Sir Alexander Fleming in 1928. Fleming observed that the mold Penicillium notatum produced a substance that could inhibit the growth of bacteria. This substance was later named penicillin and became a groundbreaking antibiotic in the field of medicine, revolutionizing the treatment of bacterial infections. Therefore, the correct answer is (B) Fungus.