Which among the following compounds are formed when an alkali metal reacts with hydrogen and halogen respectively?

The correct option is A

Metal hydride and metal halide

Alkali metals react with hydrogen to form metal hydride(MH) since hydrogen forms a hydride ion($H^{-}$).

Alkali metals react with halogens to form metal halide(MX) since halogen forms a halide ion($X^{-}$).

Hydrate means water molecules are associated with the element.