lult213 lult213 06-02-2024 Biology contestada Which of the following are nitrogen-fixing bacteria? 1. Azotobacter 2. Clostridium 3. Rhizobium 4. Cyanobacteria a) 1, 2, and 3 b) 2 and 4 c) 1, 3, and 4 d) 3 and 4