In constant prices, oil is cheaper today than the $60 a barrel in 1981, after the Iranian revolution. In the last paragraph, this means all of the following EXCEPT that ______.
A.today’s oil price is around $60 a barrel
B.in 1981, the oil price reached $60 a barrel
C.in comparison with those in 1981, today’s oil prices imposes a smaller threat
D.with $60, you could buy more in 1981