The correct option is D Monotonous
Option C)monotonous is correct as it means dull, tedious, and repetitious; lacking in variety and interest and best suits the given sentence. The other options are wrong as limited, refreshing, and innovative mean restricted in size, amount, or extent; few, small, or short, serving to refresh or reinvigorate someone, and (of a product, idea, etc.) featuring new methods; advanced and original respectively. The correct answer is C)monotonous