What effect did the Montreal Protocol have on Earth's ozone?
• It decreased ozone in the stratosphere.
• It moved the ozone hole to the other pole.
• It did not affect the ozone.
• It increased ozone in the stratosphere.
• It decreased ozone in the stratosphere.
• It moved the ozone hole to the other pole.
• It did not affect the ozone.
• It increased ozone in the stratosphere.