Why Did Banded Iron Formations Form Between 2

question 52

Multiple Choice

Why did banded iron formations form between 2.4 and 1.8 Ga?

• A)The oceans became oversaturated in iron.
• B)The oceans began to absorb large amounts of oxygen.
• C)Cyanobacteria stopped using them as nutrients.
• D)A mass extinction released iron into the oceans.

---

Definitions:

Warrants

Financial derivatives that give the holder the right, but not the obligation, to buy or sell a security at a specified price before a certain date.

Employee Options

A form of employee benefit that gives employees the right to purchase company stock at a set price at a future date.

Debt Options

Financial instruments giving the holder the right, but not the obligation, to deal with debt under specified conditions.

Calls

Options contracts giving the holder the right, but not the obligation, to buy a specified amount of an underlying asset at a specified price within a specified time.