The Answer

I will first address some concerns that people had in the comments of last post.

-The tricycle was supposed to have two wheels in the back. The two wheels lined up so well that you could only see one... also, I was too lazy to draw it in perspective on Paint.

-If there is air resistance, the bird will speed up slightly once it enters the car. What I like to do is imagine the car not as a cage of steel, but as a pocket of air going as fast as the bird. If the bird enters that pocket of air, it would be like entering a slipstream where there is less resistance to it's forward movement. So I believe that if a bird was flying next to your car and flew into the window and kept on flapping at the same rate, it would hit the windshield.

Here's what you all have been waiting for...

The answer to the tricycle problem is:

a) it will roll to the left!

Crazy, huh?

So, I guess no one won...except for kind of Anna. So you get a kind-of prize! You get honor in almost getting it right! Yay!
Is that the answer that you would have said, Chris?

I'll try to explain why it rolls forward.

Imagine that the rope was tied to the bar below the handle bars. If you pull on it, the tricycle will obviously go the direction of the pull. If you tied it to one of the pedals, and the pedal was pointing up, then it will also obviously go forward again. If you keep on pulling on the rope even when the tricycle is moving, it will continue to go forward, even when the pedal is pointing down.
This is the hard part to understand: if the pedal is pointing down and you pull on it with a rope, it will have the same effect as you pulling on the bar below the handlebars. The bike will move forward while the pedal stays in place in the horizontal direction and rises in the vertical direction.
Imagine yourself walking. Your body moves forward when one of your feet is planted on the ground, not moving. If you pulled someones thigh, there body would move without necessarily causing the pulled leg to move.












Look at the flowers in the picture as a reference point. See how the down-pointing pedal stays relatively in the same place until it loops around the top?

Physics is amazing.