Select the most appropriate option to fill in the blank.

The Intergovernmental Panel on Climate Change (IPCC) ______ the idea of ‘tipping points’ two decades ago.

introduced

The most appropriate option to fill in the blank is introduced.

The sentence is about how the Intergovernmental Panel on Climate Change (IPCC) introduced the idea of ‘tipping points’ two decades ago. The word "introduced" means "to make something known or available for the first time." This is the most appropriate word because it accurately describes how the IPCC first made the idea of ‘tipping points’ known to the public.

The other options are not as appropriate.

• Shortened means "to make something shorter." This does not make sense in the context of the sentence, because the IPCC did not make the idea of ‘tipping points’ shorter, they made it known for the first time.
• Wounded means "to hurt someone physically or emotionally." This does not make sense in the context of the sentence, because the IPCC did not hurt anyone by introducing the idea of ‘tipping points’.
• Withdrawn means "to take something back or away." This does not make sense in the context of the sentence, because the IPCC did not take back or away the idea of ‘tipping points’, they introduced it.