we are given that
Michelle plotted 3 points from the equation y = 6 on this coordinate grid
It means that y-value will be 6 irrespective of any value of x
for exp: (1,6) (2,6) (3,6) ...
so, y-value must be fixed as 6
and x-value can be anything
so, we can see that the only point which has y-value =6 is (+4, +6)
so,
option-C........Answer