D. A window the rest are incorrect
The gear ratios would look like A:B=1:9 and C:D=1:32 if you are just needing the gear teeth ratio. Not a lot of information to go off of from the question though
Don't text and drive you could crash
I suspect the answer they're looking for is false. However, as an experienced professional in learning and development, I can tell you that when done right these effects can enhance a presentation.