**Core Concept**
Nuclear dissolution refers to the process of cell death and nuclear fragmentation that occurs in response to severe DNA damage, often due to ionizing radiation. This process is characterized by the breakdown of the nuclear membrane and the dispersal of chromosomal material.

**Why the Correct Answer is Right**
The correct answer is best described as karyolysis. Karyolysis is a hallmark of nuclear dissolution, where the chromatin material becomes decondensed and stains poorly with hematoxylin in histological sections. This is due to the breakdown of the nuclear membrane and the release of chromatin into the cytoplasm. The process of karyolysis is often seen in cells that have undergone radiation-induced cell death or apoptosis.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because pyknosis is the process of nuclear condensation, where the chromatin material becomes more dense and stains intensely with hematoxylin.
**Option B:** This option is incorrect because karyorrhexis is the process of nuclear fragmentation, where the nucleus breaks apart into multiple pieces.
**Option C:** This option is incorrect because apoptosis is a type of programmed cell death, but it does not specifically refer to nuclear dissolution.

**Clinical Pearl / High-Yield Fact**
When evaluating tissue samples, it's essential to distinguish between karyolysis and karyorrhexis, as they have different implications for the diagnosis and treatment of disease.

**Correct Answer:** B. Karyolysis.