Select the most appropriate option to fill in the blank.

Global warming or climate change has today become a major to mankind.

threat

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

• Penalty refers to a punishment imposed for an offense.
• Punishment refers to the infliction of pain, hardship, or loss on someone as a punishment for an offense.
• Threat refers to a statement of intention to inflict pain, injury, damage, or other hostile action on someone.
• Endanger refers to put in danger or at risk.