Read the sentences from Last Lecture by Randy Pausch.

And if you’re curious about what zero gravity looks like, hopefully the sound will be working here. [slide shows videotape from Randy’s zero gravity experience] There I am. [laughter] You do pay the piper at the bottom. [laugher, as the people in the video crash to the floor of the plane on the video] So, childhood dream number one, check.

Why does Pausch show the audience a video of his zero-gravity experience?

A. to prove that people are curious about zero gravity
B. to show what being in zero gravity looks like
C. to prove that some astronauts do wear glasses
D. to show that being in zero gravity is painful