Nicotiana sylvestris flowers only during long days and N.tobacum flower only during long days in the labortory undre different photoperiods , they can be induced to flower at the same time and can be cross fertized to flower aat the and can be corss fertillzed to produce self - fertile offsping .What is the best reason for considering N. syvestris and N . tobacum to be separate species

Options

A. They are physiologically distinct
B. They are morphologically distinct
C. They cannot interbreed in nature
D. They are reproductively distinct

Answer

C