B: Simple -- we have never observed an effect without a cause.
First I need to drag this link into the argument...
http://whyfiles.org/shorties/133quantum_leap/
Then I need to say that the cause of the spin in the particle was created by observation. However, there was no cause for the direction of the spin. The direction of the spin was a decision made by the particle itself.. somehow. Now this decision is somehow connected with sentiency. We need to find out exactly what sentiency is, because here we have a case where observation is transmitted as a form of perpetual motion. A spin without energy transmission. When I touch my nose, I could infact say that I am observing my own particles to make them move reather than spin, and the movement could just be based on the initial spin direction which was observed in the physical test in the link. If these particles have no history, and only become active through observation, and observation is based in the present then you could say that sentiency is to be aware of the present, and only live in the present.
Now to carry this a bit further.. light is another element that requires observation to become active. Observation is a sentient force, but light is reaching the Earth from a distance that is so far away that the light is reaching Earth before sentient life lived here. So this is another case for sentience from something other than molecular life forms. How low level can sentience get?
Can sentience get low level enough for a particle to have sentience?
Can a particle observe another particle?
Once sentience is determined, you can have a decisive universe, and cause is just a matter of choice. At a very low level.. (particle level) a particle with sentience has only two choices. Spin clockwise, or spin counter-clockwise. This is a random as you can get. It's like touch your nose, touch your toes. You feel like you are making the decision, and I'm pretty sure that because sentiency occurs in the present, and has no history, that you are actually making that decision.