08. Answer: Variance and Preferred Gaussian
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Variance
The variance is a measure of Gaussian spread; the smallest spread is Gaussian B, the largest is Gaussian A. You may also notice that larger variances correspond to shorter Gaussians.
Variance is also a measure of certainty; if you are trying to find something like the location of a car with the most certainty, you'll want a Gaussian whose mean is the location of the car and with the smallest uncertainty/spread. As seen in the answer, below.

Smaller variance = more certain measurement.