The correct choice is A. I, II and III.
Here's why:
I. Inorganic fertilizers are known to increase crop yield because they provide essential nutrients that plants need to grow.
II. They can disturb the balance of nutrients in the soil when used excessively, leading to potential environmental problems and soil degradation.
III. While some inorganic fertilizers may be used in small quantities, many need to be applied in significant amounts to be effective, but they are still applied in smaller doses than organic alternatives.
IV. Inorganic fertilizers are not generally considered environmentally friendly, particularly if mismanaged, as they can lead to pollution of water bodies and degradation of soil health.
Thus, options I, II, and III are valid statements about inorganic fertilizers.