b) Ammonia (NH3) and methane (CH4) because they contain hydrogen but do not dissociate to form hydrogen ions.
Explanation:
A substance will be classified as a base according to Arrhenius theory if it produces OH (-) hydroxide ions in water. Ammonia (NH3) is a basic substance, but it is not an Arrhenius base because it does not release hydroxide ions into solution, the same happens with methane (CH4), where all four hydrogens are bound very tightly to the carbon and are not going anywhere.
