A nurse is teaching a client who is scheduled for a vanillylmandelic acid test to screen for pheochromocytoma. Which of the following statements should the nurse include in the teaching?
A) "You should avoid caffeine and nicotine for 24 hours before the test."
B) "You need to fast for 12 hours before the test."
C) "You should increase your fluid intake before the test."
D) "You need to have a full bladder for the test."