Answer the question on the basis of passage given below :
There are some deposits of nitrates and phosphates in the earth’s crust. Nitrates are more soluble in water. Nitrates are difficult to reduce under laboratory conditions, but microbes do it easily. Ammonia forms a large number of complexes with transition metals. Hybridisation easily explains the ease of sigma donation capability of NH₃ and PH₃. Phosphine is an inflammable gas, and it is prepared from white phosphorus.
Which of the following is the correct statement?

1. A Phosphates have no biological significance in humans.
2. B Between nitrates and phosphates, phosphates are less abundant in the earth's crust.
3. C Between nitrates and phosphates, nitrates are less abundant in the earth's crust
4. D Oxidation of nitrates is possible in soil.