Why Is Gold Mining Largely Unnecessary

Why is gold mining largely unnecessary?

A) Gold prices have been in a steady decline for the last 100 years.It is cheaper to buy used gold.
B) Tons of gold are already in circulation around the world.It is not necessary to mine new gold.
C) Gold is easy to find by panning rivers and other waterways.
D) Gold can be extracted from the top of the earth's crust with much less environmental impact that traditional mining methods.