Answer
I think It would be rendering
Explanation:
We can already eliminate Keyframing and tweening. Keyframes are the important frames which contain information of a start/end point of an action. Tweening in animation is a short for inbetweening, and it's the process of generating images that go between keyframes. That leaves us with smooth and render. Smoothing is just the act of making sure everything flows together. While rendering is the process of getting the final assembled animation scenes or pieces out of the computer in the format of a sequence of individual frames.
