Final answer:
For hysterosalpingography, the preferred contrast medium is water-soluble, as it ensures good imaging and reduces the risk of complications.
Step-by-step explanation:
The type of contrast medium preferred for hysterosalpingography, which is a radiographic procedure to assess the uterine cavity and fallopian tubes, is d. Water-soluble. Water-soluble contrast media are preferred because they provide good imaging results and minimize the potential for complications that may arise with other types of contrast mediums. Barium sulfate is generally used for imaging the gastrointestinal tract due to its low solubility, but it is not suitable for hysterosalpingography as it can cause granuloma formation if it enters the peritoneal cavity.