Question

which was not produced by volcanic outgassing?
a. sulfur
b. oxygen
c. carbon dioxide
d. water vapor

Explanation:

Volcanic outgassing typically releases substances like sulfur, carbon dioxide, and water vapor. Oxygen in the atmosphere was mainly produced by photosynthetic organisms (like cyanobacteria) over time, not volcanic outgassing. Sulfur, CO₂, and water vapor are common volcanic outgassing products.

Answer:

B. Oxygen