A bakery owner sells cookies by the dozen. He can bake 3 dozen cookies every hour. The graph shows the linear relationship between `y`, the number of dozens of cookies baked, and `x`, the number of hours.

The baker will bake cookies for a total of 8 hours. Which set best represents the domain of the function for this situation?

{3,9,27,36,44,81}
{1,3,4,21,56,72}
 {0,3,6,9,12,15,18,21,24} 
{0,1,2,3,4,5,6,7,8}