A nurse is providing teaching to a client who has a new prescription for transdermal nitroglycerin patches to treat angina pectoris. Which of the following instructions should the nurse include in the teaching?

A. "Remove the patch for two to four hours daily.": This is incorrect because transdermal nitroglycerin patches should be worn continuously for 24 hours, with a scheduled time to remove them (usually overnight) to prevent tolerance. B. "Apply a new patch each day after waking up.": This instruction is correct; clients should apply a new patch daily to ensure continuous therapeutic effects while also allowing a break to reduce tolerance. C. "Cover the patch with plastic wrap.": This is incorrect; covering the patch with plastic wrap can alter the absorption of the medication and is not necessary. D. "Replace the existing patch with a new patch as soon as anginal pain begins.": This is incorrect; clients should not replace the patch immediately for angina. Instead, they should use sublingual nitroglycerin for immediate relief and follow the prescribed patch schedule.