**Core Concept**
Colonic polyps are growths on the inner lining of the colon that can potentially develop into cancer. The likelihood of malignant transformation varies depending on the type of polyp. Understanding the characteristics of different types of polyps is crucial for assessing their malignant potential.

**Why the Correct Answer is Right**
The correct answer is a villous adenoma, which is a type of polyp that has a high risk of malignant transformation. Villous adenomas are characterized by a large number of villous (finger-like) projections on the surface of the polyp, which increase the risk of genetic mutations leading to cancer. The malignant potential of villous adenomas is attributed to the presence of high-grade dysplasia, which is a precancerous condition where the cells are abnormal but not yet cancerous.

**Why Each Wrong Option is Incorrect**
* **Option A:** Tubular adenomas have a lower risk of malignant transformation compared to villous adenomas. They are characterized by a tubular or glandular structure, which is less likely to develop into cancer.
* **Option B:** Hyperplastic polyps are generally considered to have a very low risk of malignant transformation. They are often found in association with other types of polyps, but their malignant potential is minimal.
* **Option C:** Serrated polyps, including sessile serrated adenomas, have an intermediate risk of malignant transformation. While they are considered to be precancerous, their risk is lower than that of villous adenomas.

**Clinical Pearl / High-Yield Fact**
Remember that the risk of malignant transformation of a colonic polyp is influenced by its histological type, size, and degree of dysplasia. Regular follow-up and surveillance are essential for patients with colonic polyps to monitor for any changes that may indicate a higher risk of cancer.

**Correct Answer:** D. Villous adenomas have a maximum chance of malignant change.