The correct option is A 7
Jean Baptiste de Lamarck and Charles Robert Darwin explained the giraffe's neck length elongation as it contains seven bones, the same as humans and many other mammals, but in giraffes, these bones are elongated.
Lamarck attributed it the 'use and disuse' theory, while Darwin was of the opinion that the long neck was a variation in the Giraffe population that survived the struggle for existence and was thus naturally selected.