A Middle Eastern Country Has an Oil Reserve That It

A Middle Eastern country has an oil reserve that it can extract for a profit of $60 a barrel today, $65 a barrel in two years, $70 a barrel in three years, and $75 in four years.The current market rate of interest is 7 percent.When should this country tap into its oil reserve to obtain the most profit per barrel in
Present value terms?

A) today
B) two years
C) three years
D) four years