Choose the incorrect statement.

(I) Plant obtains Mo in the form of MoO 2 2+ and it is the component of several enzymes including nitrogenase and nitrate reductase.

(II) The concentration of the essential elements above which plant growth is retarded is termed as critical concentration.

(III) Deficiency symptoms are structural changes in the plant due to certain element deficiency.

(IV) Deficiency symptoms disappear if the specific nutrient is provided to the plant, also if the deprivation

continues death of plant occurs.