The correct answer is: B. Charcoal
Charcoal is a form of carbon that is produced by heating wood or other organic materials in a low-oxygen environment. It is a black, porous solid that is used in a variety of applications, including water filtration, odor removal, and fuel.
Graphite is a form of carbon that is made up of layers of carbon atoms arranged in a hexagonal lattice. It is a soft, black solid that is used in a variety of applications, including lubricants, electrodes, and semiconductors.
Coke or coal is a solid fuel that is produced by heating coal in the absence of air. It is a black, porous solid that is used in a variety of applications, including iron and steel production, and electricity generation.
Carbon black is a fine, black powder that is produced by incomplete combustion of organic materials. It is used in a variety of applications, including rubber tires, printing inks, and plastics.
Charcoal is the only allotrope of carbon that is used to absorb impurities and bad odors from water and other substances. This is because charcoal has a large surface area and a high porosity, which allows it to trap impurities and odors.