According to the alternate segment theorem, angle between a tangent and a chord through a point of contact is equal to the angle in the alternate segment.
⟹∠BCX=∠BAC=40∘
Given BD∥XY
⟹∠DBC=∠BCX=40∘
Given that BD is angle bisector of angle ABC
⟹∠ABD=∠DBC=40∘
⟹∠ABC=2∠DBC=80∘