Final answer:
Friday is not a good day to administer a TB skin test if the clinic is closed on weekends because the follow-up would need to occur when the clinic may be closed.
Step-by-step explanation:
The question is asking which day is not a good day to administer a TB skin test if the clinic is closed on Saturday and Sunday. The tuberculin skin test (TST) requires a person to return to the clinic 48 to 72 hours after the test is administered to check for a reaction. Therefore, administering the test on a Friday would not be ideal because the patient would need to return on a Sunday or Monday when the clinic could be closed. This is why Friday is not a good day to administer the test.