Correct option is A
Given:
- Two chords in a circle with lengths x and y.
- Chord of length x subtends an angle of 60° at the center.
- Chord of length y subtends an angle of 90° at the center.
Solution:

Let the radius of the circle be r
Length of chord a = r ....(1) (all angles are 60°)
Length of chord b = r√2 ....(2) (chord b is making an isosceles right angle triangle)
From equation 1 and 2
b = a√2