Q7. Match the following associations involved in dinitrogen fixation with their representative genera:
Associations Genera
1. Heterotrophic nodulate i) Azotobacter
2. Heterotrophic non-nodulate ii) Frankia
3. Phototrophic associative iii) Nostoc
4. Phototrophic free-living iv) Rhodospirillium
A) 1 -ii; 2-i; 3-iv; 4-iii
B) 1 -iii; 2-i; 3-ii; 4-iv
C) 1 -i; 2-ii; 3-iii; 4-iv
D) 1 -ii; 2-i; 3-iii; 4-iv