Final answer:
The complete melting of the white Arctic sea ice would lead to an increase in Arctic Ocean temperatures due to the exposure of dark ocean water that absorbs more solar radiation.
Step-by-step explanation:
If global warming results in the complete melting of the white Arctic sea ice, the effect on Arctic Ocean temperatures would be c) Increase in temperatures. Light-colored surfaces like ice have a high albedo, meaning they reflect a significant portion of solar radiation. The Arctic sea ice melting would expose darker ocean water that absorbs more solar radiation, leading to a rise in temperatures due to a positive feedback mechanism. This increase in temperature worsens global climate change and accelerates the melting of polar ice, contributing to global sea level rise and further temperature increases.