Data Sufficiency (DS) | Re: AC is a diameter of the circle and B is a point on the circle. ACD is

I went with answer A. AB=AC implies that it is an isosceles triangle with 45 degree angles at BCA and BAC.

St2 is insufficient, CD could be extremely far away and thus making the degree of BDC smaller. We'd also need to know the angle of ABD, which we don't have.

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