$3$

$9.$ Please select the option which exemplifies the appropriate boundary values.

A given booking system rejocts the reservations if the customer attempts to book a chow before $10$:$00,$ however if the customer makes the booking for the shows between $10$:$00$ and $21$:$00,$ the bookings are accepted, an the other hand if the booking time requested is at or after $22$:$00$ the bookings are rejected.

A: $9,10,11,22$

B:$9,10,21,22$

c$.10,11,21,22$

D: $10,11,20,21$