Answer:

Introduction:
NH4 is the chemical formula for ammonium, which is a positively charged ion. In order to determine the types of bonds present in NH4, we need to analyze the nature of the bonds formed between the atoms in the ammonium ion.

Bond Analysis:
The ammonium ion (NH4+) consists of one nitrogen atom (N) and four hydrogen atoms (H).

Covalent Bonds:
Covalent bonds occur when two atoms share a pair of electrons. In NH4, each hydrogen atom shares one electron with the nitrogen atom, resulting in four covalent bonds between nitrogen and hydrogen. Therefore, NH4 has four covalent bonds.

Coordinate Bond:
A coordinate bond, also known as a dative bond, occurs when one atom donates both electrons in a shared pair to another atom. In NH4, the nitrogen atom possesses a lone pair of electrons, which it donates to form a coordinate bond with a proton (H+) from another molecule. However, in the given question, there is no mention of NH4 forming a coordinate bond. Therefore, the presence of a coordinate bond cannot be assumed.

Ionic Bond:
An ionic bond occurs when there is a complete transfer of electrons from one atom to another, resulting in the formation of ions. In NH4, the nitrogen atom accepts an electron from each of the four hydrogen atoms, leading to the formation of a positively charged ammonium ion (NH4+). The transfer of electrons from hydrogen to nitrogen results in the formation of four ionic bonds between hydrogen and nitrogen. Therefore, NH4 has four ionic bonds.

Conclusion:
Based on the analysis, the correct answer is option 'D': Three covalent bonds and one coordinate bond. However, it is important to note that the given options are not entirely accurate. The correct answer should state that NH4 forms three covalent bonds and one coordinate bond, rather than four ionic bonds.