The correct option is B 5
Half of perimeter
=202=10 cm
Now, we have to find number of rectangles that can be drawn, such that the sum of its length and breadth is 10 cm.
All possible pairs of length and breadth are,
(1,9), (2,8), (3,7), (4,6), (5,5)
Hence, 5 rectangles can be drawn.
Remember - Squares are also rectangles.