The things common to Azotobacter, Anabaena, Nostoc and Frankia areA. ProkaryotesB. BGAC. N2 fixer
Only (A) and (B) are correct.
Only (C) is correct.
Only (A) and (C) are correct.
(A), (B), and (C) are correct.
Azotobacter, Anabaena, Nostoc and Frankia are prokaryotes and they are nitrogen fixers as well.