The move from the was a factor which led to the energy crisis, because opec began to price a barrel of oil against gold.
a. gold standard
b. fluid exchange
c. global currency
d. fixed exchange

The answer is letter a. gold standard. 
The move from the gold standard was a factor which led to the energy crisis, because OPEC began to price a barrel of oil against gold.

A gold standard is a monetary system whereby the standard economic unit of account is based on a fixed quantity of gold. 

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