Once opened, the bottlemust be dated and discarded after how many months?

When teaching post MI patients about their NTG tablets, theclinician should stress that the tablets should remain in thelight-resistant bottle in which they are packaged and shouldnot be put in another pill box or remain in areas that are orcould become warm and humid. Once opened, the bottlemust be dated and discarded after how many months?
a. 1 month
b. 3 months
c. 6 months
d. As long as the tablets are kept in this special bottle, they will last forever