Read the following statements, and choose the correct options.
A. Many members of the genus Glomus form mycorrhiza.
B. Aulosira is a non-symbiotic nitrogen fixer in rice field.
C. BGA also adds organic matter to the soil and increase its fertility.

• A

  Only A is correct.

• B

  Only A and B are correct.

• C

  Only B is incorrect.

• D

  A, B and C are correct.