The Primary Source of Oxygen for the Earth's Atmosphere During

question 23

Multiple Choice

The primary source of oxygen for the earth's atmosphere during the past half billion years or so appears to be

• A) volcanic eruptions.
• B) photosynthesis.
• C) photodissociation.
• D) exhalations of animal life.
• E) transpiration.

---

Definitions:

DE-style Equations

Mathematical formulations used in differential equations, often in the context of dynamic systems or mathematical physics.

Lanoxin

A brand name for digoxin, a cardiac glycoside used to treat heart conditions such as atrial fibrillation and heart failure.

Digoxin

A drug employed to manage multiple cardiac disorders, such as atrial fibrillation and heart failure.