The correct answer is B. Tetra-atomic.
Phosphorus is a chemical element with the symbol P and atomic number 15. It is a non-metallic, pale yellow, tetravalent metalloid in the nitrogen group. It is found in nature as the free element as well as in minerals such as phosphate rock. Phosphorus is a major component of adenosine triphosphate (ATP), the molecule that provides energy to cells. It is also used in fertilizers, pesticides, and explosives.
The atomicity of an element is the number of atoms that make up a molecule of that element. The atomicity of phosphorus is four. This means that a molecule of phosphorus contains four atoms of phosphorus.
The other options are incorrect. Option A is incorrect because phosphorus is not a monoatomic element. Option C is incorrect because phosphorus is not a diatomic element. Option D is incorrect because phosphorus is not a polyatomic element.