Phil the Medical Assistant Is at the Patient's Bedside

Phil the Medical Assistant is at the patient's bedside. While completing the label of the blood specimen he just drew, Phil realizes he wrote the wrong date. He puts a line across the wrong entry, adds his initials at the end of the line, and writes the correct date above the incorrect date. What, if anything, has Phil done wrong?

A) Phil has not done anything wrong.
B) Phil should have kept the label neat by whiting-out the wrong date.
C) Phil should have gone back to the lab for a new label.
D) Phil should make a very black box over the wrong date, so as not to cause confusion.