Pick the odd one out from the following:

NaOH is the odd one out because sodium hydroxide is a strong base and dissociates almost completely in aqueous solution. In comparison, Cu(OH)2 and Zn(OH)2 are sparingly soluble hydroxides, while NH4OH (aqueous ammonia) behaves as a weak base. Thus, among the given options, NaOH is distinguished by its strongly basic character.