A group of organisms which has been reclassified is:

O Mallard duck

O Canis familiaris

O English sparrow

O Domesticus passer

B. Canis familiaris

Explanation - Canis familiaris has been reclassified. Canis familiaris is a species of dog. It has been reclassified stating that the dogs have evolved from wolf, Canis lupus. From Canis familiaris, the scientific name was changed to Canis lupus familiaris. To check the ancestors of species, phylogenetic relationship between the species is studied.

Even the morphology and genetic constitution of the species are studied to understand the similarity between the species. Similarly, in this study, wolf is considered to be the ancestor of dogs.