What is the tone of this selection? One Giant Leap for Mankind

A. playful

The scene is meant to be funny and the seriousness of the human characters is the classic "straight man" to the chimpanzee's buffoonery.

If you analyze funny scenes / acts, you'll see that there is often a buffoon who says wild things and a "straight man" who doesn't get the joke. This makes the audience feel very clever and it laughs.