The following set of random numbers represents 20 simulations of 3 daily flights from philadelphia to seattle, with 0, 1, 2, or 3 representing a late departure and 4, 5, 6, 7, 8, or 9 representing an on-time departure. in how many of the simulations was there an on-time departure for all 3 flights?

506 619 535 769 096 380 527 555 737 192 092 658 694 320 442 812 968 763 374 282

a. 4
b. 3
c. 5
d. 6