The graph shows the number of hours that Tammy spends typing for work, x, and the amount of pay that she earns, y. On a graph titled Tammy's Pay, number of hours is on the x-axis and pay in dollars is on the y-axis. A line goes through points (2, 18) and (8, 42).

What does the y-intercept represent?
Tammy initially had $10 pay.
Tammy will type for 10 minutes each day.
Tammy initially had $4 pay.
Tammy will type for 4 minutes each day.