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OA: D
[spoiler]In the explanation given, the distance between the two circles (line OQ) is taken to be the radius of the circles. On eyeballing, yes it appears that circumference of circle Q goes through center point O (and vice-versa). But as this is not explicit (i think) in the question, isn't it wrong to assume that distance OQ is the radius?? [/spoiler]
Source: Knewton.


















