What type of waves have a wavelength greater than 1.73 cm, with gravity and momentum as the restoring forces?

Gravity waves are characterized by having a wavelength greater than 1.73 cm, where gravity acts as the restoring force. These waves are formed when the surface tension of water is overcome by gravitational forces. They can occur in various contexts, such as in the open ocean, where long wavelengths result from the wind's energy transferring to the water surface. The energy from the wind causes disturbances that lead to the formation of these larger waves, which can carry significant energy over vast distances.

These waves differ from capillary waves, which have shorter wavelengths (typically less than 1.73 cm) and are primarily restored by surface tension. Deep and shallow waves involve the influence of water depth, but in the context of this question, gravity waves specifically refer to longer wavelengths where gravity plays the dominant restoring role. Thus, among the provided options, gravity waves are the correct choice due to their defining criteria of wavelength and restoring forces.