The answer to this question is A but I put D as there’s a possibility that AC and AD are diameters as well and if we were to average two diameters together, we’d get the diameter measure as the answer. Love to hear other interpretations!
No, because there is only one diameter to a circle at a certain point. It can be shown that AC < AB and AD < AB.
As a result, the mean of AC and AD must also be less than AB.