Answer: Option C. "Sublingual"
Step-by-step explanation:
Nitroglycerin act as vasodilatory drug which is used to provide relief from acute angina administered as a tablet which is absorbed sublingually for out-patient.
Acute angina may be defined as the discomfort condition of chest due to poor blood flow through blood vessels or coronary vessels of the heart muscle.
Nitroglycerin is prescribed to take sublingually for acute anginal chest pain prior to any event that can provoke symptoms of angina. The instructions are given that allow the nitroglycerin to dissolve in the mouth and then oral mucosa is allow to absorb the drug. After the administration, onset of vasodilatory drug effects take place within 1 to 3 minutes or a maximum effect occurs within 5 minutes.
Hence, the correct answer is option C.