The graph represents the direct variation function between earnings in dollars and hours worked. A coordinate plane showing Store Clerk Pay, Hours Worked on the x-axis and Total Earnings in dollars on the y-axis. A line starting at (0, 0) and passing through (4, 30), (8, 60) and (12, 90)
Which equation can be used to describe the direct variation function between E, the total earnings in dollars, and h, the number of hours worked?

E = 1.5h
E = 7.5h
E = 13h
E = 15h