Final answer:
The sea level would rise by approximately 6.76 meters if the Greenland ice sheet completely melted and the released water spread out over Earth's oceans.
Step-by-step explanation:
To calculate how much the sea level would rise if the 2.3 million cubic kilometers of water from the melted Greenland ice sheet were spread over the Earth's approximately 340 million square kilometers of ocean surface, we divide the volume of water by the ocean surface area. This calculation gives us:
Sea level rise = Volume of water / Ocean surface area
Sea level rise = 2.3 million km³ / 340 million km²
Sea level rise = 0.00676 km
Converting kilometers to meters (1 km = 1000 m), the sea level rise would be:
Sea level rise = 0.00676 km * 1000 m/km
Sea level rise = 6.76 m
Therefore, the correct answer is b. Approximately 6.76 meters.