Which relation is a function? NEED HELP ASAP PLS

{(0, 2), (0, 4), (0, 6), (0, 8)}

{(1, 2), (2, 3), (3, 4), (4, 5)}

{(1, 2), (2, 1), (1, 3), (3, 1)}

{(1, 2), (3, 4), (5, 6), (1, 8)}

Find the volume of the solid generated when the region bounded by y= x and y= 4√x is revolved about the x-axis the volume of the solid is: (type an exact answer cubic units)

Iwill give brainliest. suppose tommy walks from his home at (0, 0) to the mall at (0, 5), and then walks to a movie theater at (6, 5). after leaving the theater tommy walks to the store at (6, 0) before returning home. if each grid square represents one block, how many blocks does he walk?

What is the area of the shaded sector?