Correct option is B
• Assertion (A): "Ozone hole is observed only over Antarctica."
The severe depletion of the Antarctic ozone layer known as the “ozone hole” occurs because of the special atmospheric and chemical conditions that exist there and nowhere else on the globe.
• Reason (R): "Ozone layer is found in the lower portion of the stratosphere layer of the atmosphere."
This statement is true. The ozone layer is indeed located in the lower part of the stratosphere, typically between 15 to 35 kilometers above Earth's surface.
