The value of a bottle of wine, if stored properly, rises by 5 dollars a year for the next 50 years. Storage costs are 0.50 dollars per year. If at the moment of production the price of this bottle of wine is 5 dollars and the interest rate is 5% then how old will be the bottle of wine if sold by rational investors?

a. 50 years old

b. 20 years old

c. 30 years old

d. None of the other answers

e. 90 years old