Imagining the shapes visually might prove to be another way of doing this.
The question translates into - Is there only ONE possible line that satisfies the given figure spatially.
(1) When \angle COD
is fixed, there can be many lines possibly drawn from C to A, but only one line would render length AB = radius
(2) When \angle BCO
is fixed, the same reasoning applies.
So now we know that in either of the cases, we CAN zero down to one particular line segment, wich means that \angle BAO
is fixed (whatever it be). So answer is D.
In a Normal Distribution, only the Average 'Stand Out'