What is one of the characteristics of hydrophobic mounting mediums?

Hydrophobic mounting mediums are characterized primarily by their interaction with water. Option B, which states that they are soluble with xylene, is correct because hydrophobic mediums are designed to work with organic solvents such as xylene, which is commonly used in histological procedures for clearing tissues.

These mediums do not mix well with water, making them particularly useful for maintaining the clarity and integrity of the specimen when using organic solvents. This property is essential when preparing slides for microscopic examination, as it prevents distortion and allows for improved visualization of the specimen.

In contrast, hydrophobic mounting mediums do not dissolve in water (which aligns with the characteristic of being hydrophobic), they do not retain moisture (which would be incompatible with their intended uses), and they typically are not used for fat stains, which often require a different type of medium that allows for lipid preservation and visualization. Therefore, the focus on xylene solubility highlights the nature of these mounting mediums and supports their primary application in histology and microscopy.