When Someone Tells You They Made $17,000 in 1970

When someone tells you they made $17,000 in 1970:

A) it is difficult to tell from that number if the person was well off or not, because prices have changed so much since then.
B) the income should be adjusted into current dollars to clearly understand what that salary is "worth" in terms of purchasing power.
C) it is a nominal figure that is hard to understand. A real figure would be more helpful.
D) All of these statements are true.