Case Study question

This may seem like a no brainer question, but I feel like either I'm overthinking it or missing something completely, so I am looking for some help. I am doing a cardiac case study and my patient has just been discharged with an order for nitro. The question asks what statement would show that the patient requires further teaching?

a) "At the first sign of chest pain, I will stop what I'm doing and sit down"

b) "I will place one nitroglycerin tablet under my tongue"

c) "If the chest pain does not stop, I can take another tablet in 5 minutes"

d) My husband will need to call 911 if the chest pain does not stop after three nitro tablets"

Now, at first I thought A; because many doctors tell you that you should take the nitro before activities that could cause angina and therefore head the pain off- but the question doesn't ask about that and I feel I'm reading into it too much.

B is correct as far as I know.

C gave me pause only because some doctors want you to call then after the first dose does not work and they may tell you to go right to the ER rather than take another dose after waiting 5 minutes. Again, reading too much?

D is correct, I believe.

So is this a trick question?? All answers seem fairly reasonable to me. Sorry if this is a bonehead question but I could use some input! Thank you :)