When the ends of the rope are moved up and down faster while keeping the same distance of movement, the frequency of the waves increases. As a result, the wavelength decreases because the waves are being generated more frequently in the same time period. The amplitude, which is the height of the waves, would remain unchanged because the distance the rope is moved up and down remains the same.
Based on this explanation, the correct response is:
The frequency would increase and the wavelength would decrease, but the amplitude would be unchanged.