B. Sensor bar.
The triaxial accelerometers are highly accurate, but they only know how much and in what direction they have moved, not where they are, which would require the developer to find some way of getting the user to tell the device where it is,(Calibration) for more intricate interaction.
The sensor bar, uses a set of eight LED's (much to my surprise, apparently, Jim Merrick didn't quite understand how the sensor bar worked when he let his mouth run in an IGN article. "Uses blue tooth to trilaterate position", oh well, Public representatives aren't engineers, and these things happen).
Now, these IR LED's are picked up by an optical sensor at the end of the Wii remote. This is used to determine the distance to the remote. This information alone is more or less useless, but combined with the information in the remote, (angle) the Wii can establish an angle, and a distance, from the remote, to the led. That is eight points, with 8 distances. But accurate trilateration requires the known points not be in a single plane, or line. But this is the beauty of the sensor bar accelerometer combo.
If you have a line, and you know the angle, and distance of the line, you can intersect that line with a generated perpendicular line, of any assigned length. This would create a right triangle, the vertex being the end of the generated line, and having 2 known sides, the unknown side being the hypotenuse. A^2+b^2=c^2. We now have a distance to the generated point. This process can be duplicated an infinite amount of times (most probably well over 30 times a second.), as long as the Wii remote sensor can see the led. All those generated points can practically be described as, well, a field of points. Making accurate trilateration pretty easy, as long as one led from each side isn't blocked from view. Fortunately, even with the sensor bar hidden from view, all a developer needs to do is feed the last acquired co-ordinates to the accelerometers, this should provide more than accurate compensation until the line of sight is restored. Nintendo's E3 sensor bar was huge, and as a result, the remote would have trouble acquiring input from the sensor bar. in order to acquire distance, the Wii remote would have to be far enough away to acquire an led on each side, or point the remote at the sensor bar. As everyone has seen, Nintendo has seriously shrunk the size of the sensor bar since.
I wonder if any relationships will be formed through Mii's
So they're not.