In Figure, if PQR is tangent to a circle at Q whose center is O, AB is a chord parallel to PR and BQR = 70°, then 
 AQB is equal to

(A) 20°                        (B) 40°                        (C) 35°                        (D) 45°
                
                  Answer(B)                        
Solution
Given :, 
Since DQ perpendicular to PR
Since DQ bisect 
Hence ,