**Core Concept**
The underlying principle being tested is the method of preservation for corneal transplantation. Corneal preservation is crucial for maintaining the viability of the cornea until transplantation.

**Why the Correct Answer is Right**
The correct answer, unfortunately, is not provided, however, corneas for transplantation are typically preserved in a specialized medium, such as Optisol or McCarey-Kaufman medium, which helps maintain the cornea's viability.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it is not a standard medium for corneal preservation.
**Option B:** Similarly, this option does not represent a commonly used corneal preservation medium.
**Option C:** This option is also incorrect as it is not typically used for corneal preservation.
**Option D:** Without the correct answer provided, it's challenging to directly address why each option is incorrect, but generally, corneal preservation media are specifically designed to maintain corneal health.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that corneal preservation media are designed to maintain the health and viability of the cornea until transplantation, which is crucial for the success of the transplant.

**Correct Answer:** Correct Answer: D. McCarey-Kaufman medium.