The answer to your question is D
Answer:
Nitrate
Nitrate is the form of nitrogen most used by plants for growth and development. Nitrate is the form that can most easily be lost to groundwater. Ammonium taken in by plants is used directly in proteins. This form is not lost as easily from the soil.
Explanation:
One electron is transferred in the ionic bond because sodium needs to lose one electron and chlorine needs to gain one electron to have a full energy shell, which is the ultimate goal in any bond.
Brainliest please :)