Explanation:

All codes are correct.
Impact of Melting Arctic Ice
1) Global Climate Change:

• The Arctic and Antarctic act like the world’s refrigerator. They balance out other parts of the world that absorb heat. The loss of ice and the warming waters will affect sea levels, salinity levels, and current and precipitation patterns. 

2) Danger to Coastal Communities:

• Global average sea level has risen by about 7-8 inches since 1900, and it’s getting worse.
• Rising seas endanger coastal cities and small island nations by exacerbating Coastal Flooding and storm surge. 

3) Food Security:

• Polar vortexes, increased heat waves, and unpredictability of weather caused by ice loss are already causing significant damage to crops on which global food systems depend. 

4) Loss of Methane Store:

• Permafrost in the Arctic region (ground that is permanently frozen) stores large amounts of methane, which is a greenhouse gas that contributes to climate change.
• As more quickly the arctic ice is lost, more rapidly permafrost will melt. This will result in a vicious cycle that may result in a climate catastrophe.

5) Biodiversity Threat:

• Melting of the Arctic ice puts the Arctic region’s vibrant biodiversity under serious threat.

Hence option 4th is correct.