Answer:
3rd option
Step-by-step explanation:
Cavalieri's principle states that two figures which have the same height and same cross-sectional area have the same volume
the height of the cylinders are both 42
the diameter of both figures is 24 as the diameter of the second cylinder = 12 x 2 = 24
the radius of the cylinders are both equal to 12
the diameter is the straight line that passes through the centre of a circle and touches the two edges of the circle.
A radius is half of the diameter
thus the volumes should be equal