First mammal to be cloned was -

The first mammal to be successfully cloned from an adult somatic cell was a sheep named Dolly. Born on July 5, 1996, at the Roslin Institute in Scotland, Dolly was created by scientists Ian Wilmut and Keith Campbell using a process called somatic cell nuclear transfer (SCNT). This groundbreaking achievement proved that specialized adult cells could be reprogrammed to create a new organism, overturning previous scientific beliefs. While frogs were the first vertebrates cloned in 1952, they are amphibians, not mammals. Similarly, goats and rats were cloned later in the 1980s and 1990s, but Dolly remains historically significant as the first mammal. Therefore, Option A (Sheep) is the correct answer.