A group of animals that are related by descent and similar in most characters like general appearance, size, features, etc., are said to be a breed. For example; Leghorn is the improved breed of chicken. Race is a geographically isolated breeding population that shares common features in higher frequencies.Variety is a taxonomic rank below that of species or sub-species but used in the case of plants.A species is a group of closely related organisms that are very similar to each other and usually capable of interbreeding. So, the correct option is 'Option A' .