Which set is a function?

a)
{(0,3), (3,0), (0,4), (4,0)}

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

c)
{(2,6), (3,6), (4,6), (2,0)}

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

Does the construction demonstrate how to copy an angle correctly using technology a) yes the distance between points a and f was used to create circle h b) yes the distance between points f and g was used to create circle h c) no the distance between points a and f was used to create circle h d) no the distance between points f and g was used to create circle h