Answer:
c. (π/2 -1) square units
Explanation:
A segment that subtends an arc of θ in a circle of radius r has an area given by ...
A = (1/2)(θ -sin(θ))r² . . . . . where θ is in radians
In your figure, the radius is r = √2 and the angle is 90°, so θ = π/2. Then the area is ...
A = (1/2)(π/2 -sin(π/2))·(√2 units)²
A = (π/2 -1) units²