The correct option is B 126∘
Since angle in a semicircle is a right angle, we have
∠ABC=90∘.
But, ∠ABD+∠DBC=∠ABC
i.e., ∠ABD+36∘=90∘
⟹∠ABD=54∘
Consider the cyclic quadrilateral ABDE. Since opposite angles are supplementary, we have
∠ABD+x=180∘
⟹x=180∘–54∘=126∘