Let PQRS be a rectangle and ABCD be a rhombus which is formed by joining the mid points of a rectangle.
Given Area of rhombus =2 unit. But Area =
1
2
×d1×d2=2 d1d2=2×2=4 units where d1= diagonal ACd2= diagonal BD But AC= Breadth of rectangle BD= length of rectangle ⇒ Area of rectangle =AC×BD =d1×d2 =4 units ,∴ option (b) is correct.