A.54 pie cm^3

B.72 pie cm^3

C.126 pie cm^3

D.378 pie cm^3

Explanation:

The radius of each sphere is r = 3

The volume of one sphere is

V = (4/3)*pi*r^3

V = (4/3)*pi*3^3

V = 36pi

That's the volume of one sphere.

Three spheres take up 3*36pi = 108pi cm^3 of space.

The radius of the cylinder is also r = 3, since each tennis ball fits perfectly in the container.

The height is h = 18 because we have each ball with a diameter 6, which leads to the three of them stacking to 3*6 = 18.

The volume of the cylinder is...

V = pi*r^2*h

V = pi*3^2*18

V = 162pi

Subtract the volume of the cylinder and the combined volume of the spheres:  162pi - 108pi = (162-108)pi = 54pi

This is the exact volume of empty space inside the can.

This points to choice A as the final answer

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