Based on Historical Data on the Prices of Natural Resources

Based on historical data on the prices of natural resources, which of the following best describes how natural resources limit economic growth?

A) Prices have been increasing, which shows that natural resources become scarcer and this impedes growth.
B) Prices of natural resources have been fluctuating, which shows that there is no correlation between growth and natural resources.
C) Prices of natural resources have been decreasing in constant dollars, which shows that natural resources are not scarcer than they were in the past, thus economic growth is not limited by natural resources.
D) Prices do not show whether resources limit growth because the natural resources that economies use are not the same today as those in the past.