Which of the Following Statements About Performing Cryosurgery for Actinic

Which of the following statements about performing cryosurgery for actinic keratosis is true?

A) It is better to slightly overfreeze the area, so you only have to do it once.
B) Using liquid nitrogen, freeze each lesion for at least 30 seconds.
C) Every lesion should be biopsied after using liquid nitrogen.
D) The "freeze balls" should be approximately one-and-a-half times as wide as they are deep.