Question

what gas has increased in concentration in the atmosphere since the beginning of the industrial revolution?

a. nitrogen

b. carbon dioxide

c. oxygen

d. neon

Explanation:

Since the Industrial Revolution, human activities like burning fossil fuels (coal, oil, gas) have released large amounts of carbon dioxide ($\ce{CO_2}$) into the atmosphere. Nitrogen, oxygen, and neon have relatively stable atmospheric concentrations and are not significantly increased by industrial activities. So the gas with increased concentration is carbon dioxide.

Answer:

B. Carbon dioxide