Which of the Following Statements About the Banded Iron Formations

Multiple Choice

Which of the following statements about the banded iron formations is true?

A) The BIFs show evidence of an oxygen-poor atmosphere because all of the oxygen was dissolved into the oceans and then precipitated as iron-oxide minerals.
B) The BIFs show evidence of an acidic ocean that forced iron to bond with the oxygen in the water to form iron-oxide minerals.
C) The BIFs show evidence of an oxygen-poor ocean because all the oxygen was trapped in the iron-oxide minerals that make up the formation.
D) The BIFs show evidence of an oxygen-rich atmosphere that forced the oceans to become oxidizing and precipitate iron-oxide minerals.