The correct answer is $\boxed{\text{A}}$. Ammonium chloride (NH4Cl) is an ionic compound that contains both ionic and covalent bonds. The ammonium ion (NH4+) is formed when ammonia (NH3) loses one electron to form a positive charge. The chloride ion (Cl-) is formed when chlorine (Cl2) gains one electron to form a negative charge. The ammonium and chloride ions are held together by an ionic bond, which is a strong electrostatic attraction between oppositely charged ions. The covalent bonds in ammonium chloride are formed between the nitrogen atom in the ammonium ion and the hydrogen atoms in the ammonia molecule. These bonds are formed by the sharing of electrons between the nitrogen and hydrogen atoms.
The other
options are incorrect because they do not contain all three types of bonds. Option $\text{B}$, sulfur trioxide (SO3), is a covalent compound that contains only covalent bonds. The sulfur atom in sulfur trioxide is bonded to three oxygen atoms by covalent bonds. Option $\text{C}$, sulfur dioxide (SO2), is also a covalent compound that contains only covalent bonds. The sulfur atom in sulfur dioxide is bonded to two oxygen atoms by covalent bonds. Option $\text{D}$, water (H2O), is a covalent compound that contains only covalent bonds. The hydrogen atoms in water are bonded to the oxygen atom by covalent bonds.