Q. Which of the following adds / add nitrogen to the soil?
1. Excretion of urea by animals
2. Burning of coal by man
3. Death of vegetation
Select the correct answer using the codes given below.

[A] 1 only

[B] 2 and 3 only

[C] 1 and 3 only

[D] 1, 2 and 3

Answer: C