Right Answer is: B
In the diagram shown above, triangle ABC is right angled triangle. So ∠ACB= 90, ∠BAC = 25°
Then, ∠ABC = 180 – (90+25) = 65
As given that ABCD is a trapezium so, CD must be parallel to AB.
Hence, ∠DCA = ∠BAC = 25
Using cyclic quadrilateral theorem, sum of opposite angles of cyclic quadrilateral is 180.
So, ∠ADC + ∠ABC = 180
∠ADC + 65 = 180
∠ADC = 115
In triangle ADC, sum of angles ∠CAD + ∠ACD + ∠ADC = 180
∠CAD + 25 + 115 = 180
∠CAD = 180-140 = 40
Hence, option B is the correct answer.