**Core Concept**
The question tests the concept of density and osmolality in relation to the behavior of eggs in different solutions. The density of an object determines whether it sinks or floats in a fluid. Osmolality, which is the concentration of osmotically active particles in a solution, affects the movement of water into or out of cells.

**Why the Correct Answer is Right**
Eggs float in a saturated solution of saline because the density of the egg is less than that of the solution. This is due to the high osmolality of the saline solution, which causes water to move out of the egg, reducing its volume and making it float. The correct answer is an egg that does not undergo this process.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because eggs that are not treated with a substance that alters their density will still float in a saturated solution of saline.
**Option B:** This option is incorrect because eggs that are not affected by the osmolality of the solution will still undergo the process of floating in saline.
**Option C:** This option is incorrect because eggs that are denser than the solution will sink, not float.

**Clinical Pearl / High-Yield Fact**
In a clinical setting, the behavior of eggs in different solutions can be used to assess the osmolality of a solution. This is particularly useful in critical care medicine, where maintaining proper osmolality is crucial for patient care.

**Correct Answer: C. Egg that is denser than the solution.