Here's a problem to solve: Due to the increasing average temperature of the atmosphere, polar ice sheets melt at a greater rate than they form. Which of these will be an effect of the continued melting of polar ice?

Among the 4 following options, which is the correct answer?

- A: A major reservoir of fresh water will decrease.
 
- B: Plant life will increase due to higher sea levels.
 
- C: Water runoff will cause an increase in ocean salinity.
 
- D: Ocean temperature will decrease with the addition of cold water.
 