The correct option is A.
The observation that the embryos of certain species have physical and genetical similarities in the earliest stages of embryonic development shows that individual development of an organism shows its revolutionary history and this is taken as an evidence of common ancestry. Scientists takes this observation to mean that all life on earth developed from a single ancestor.<span />
Symbiosis is a close relationship between two species in which at least one species benefits. For the other species, the relationship may be positive, negative, or neutral. There are three basic types of symbiosis: mutualism, commensalism, and parasitism.
Mutualism
Mutualism is a symbiotic relationship in which both species benefit. An example of mutualism involves goby fish and shrimp
