BA and BD are radii of the circle, so triangle ABD is isosceles. Then angles BDA and BAD are congruent, and the remaining (central) angle ABD has measure

Angles ABD and CBD are supplementary, so

and the answer is E.
Depends on the type of AB, is it AB positive or AB negative
<span>AB-positive: 3.4 percent
<span>AB-negative: 0.6 percent
if you need both add the percentages together</span></span>