The correct answer is: B. Molecular hydrides
Molecular hydrides are compounds formed when hydrogen combines with p-block elements. They are typically non-polar and have low boiling points. Some examples of molecular hydrides include water (H2O), ammonia (NH3), and methane (CH4).
Ionic hydrides are compounds formed when hydrogen combines with electronegative elements such as oxygen, fluorine, and chlorine. They are typically highly polar and have high boiling points. Some examples of ionic hydrides include sodium hydride (NaH) and lithium hydride (LiH).
Metallic hydrides are compounds formed when hydrogen combines with metals. They are typically non-stoichiometric and have variable properties. Some examples of metallic hydrides include palladium hydride (PdHx) and nickel hydride (NiHx).
Polynuclear hydrides are compounds formed when hydrogen combines with two or more p-block elements. They are typically highly reactive and have complex structures. Some examples of polynuclear hydrides include borane (B10H14) and diborane (B2H6).