"That's just the tip of the iceberg" is a popular expression you may have heard. It means that what you can see is only a small part of the overall problem. As the diagram shows, most of an iceberg is actually out of sight, below the water level. Although we can’t prove how the expression originated, early 20th-century uses of this expression are believed to have been influenced by the sinking of the Titanic when it struck an iceberg on its maiden voyage in 1912.

To determine the best prediction for the density of the iceberg, we'll use the principle of buoyancy. An object will float if its density is less than that of the fluid it is in.

Since the density of seawater is given as 1.03 g/mL, for the iceberg to float, its density must be less than 1.03 g/mL.

Let's evaluate the responses:
- **1.16 g/mL** - This is greater than 1.03 g/mL, so it wouldn’t float in seawater.
- **0.96 g/mL** - This is less than 1.03 g/mL, which means that this density is possible for an iceberg.
- **1.25 g/mL** - This value is also greater than 1.03 g/mL, thus not possible for an iceberg floating in seawater.
- **0.23 g/mL** - This is also less than 1.03 g/mL and could be a plausible density.

However, considering common estimates for ice density (typically around 0.92 g/mL), the most appropriate choice among those listed would be **0.96 g/mL**, as it is a realistic density for an iceberg that floats in seawater.

So, the best prediction for the density of the iceberg is **0.96 g/mL**.