Answer:
Option: B is the correct answer.
B. 5 units.
Step-by-step explanation:
Rectangle ABCD translates 4 units down and 2 units to the right to form rectangle A'B'C'D'.
We know that when a figure is translated by some units then the coordinates of the figure changes but the size and shape of the figure remains the shape.
The size is changed when we are dilating a figure.
If AB=3 units and AD=5 units.
Then as ABCD is a rectangle.
Hence,
BC=AD
Hence, BC=5 units.
Also we know that:
ABCD → A'B'C'D'
i.e. BC → B'C'
Hence, Length of BC=Length of B'C'.
Hence, B'C'=5 units.