**Core Concept**
The T.N.M. classification is used to stage breast cancer, with T representing the size and extent of the primary tumor. In this context, the T classification is crucial in determining the extent of the disease and guiding treatment decisions.

**Why the Correct Answer is Right**
The presence of cutaneous edema (peau d' orange) indicates skin involvement, which is a characteristic of T4 breast cancer according to the T.N.M. classification. This is because T4 tumors are defined as those that have extended to the chest wall and/or caused skin changes, such as peau d' orange, ulceration, or satellite skin nodules. The size of the tumor is not the only factor in determining the T classification, but rather the extent of its involvement with surrounding structures.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because T1 tumors are typically less than 2 cm in greatest dimension, which does not apply to this case.
**Option B:** This option is incorrect because T2 tumors are typically 2-5 cm in greatest dimension, but the presence of cutaneous edema indicates a more extensive disease.
**Option C:** This option is incorrect because T3 tumors are typically greater than 5 cm in greatest dimension, but the presence of skin involvement is a more significant factor in determining the T classification.

**Clinical Pearl / High-Yield Fact**
In breast cancer, the presence of skin changes such as peau d' orange is a significant indicator of advanced disease, warranting further evaluation and aggressive treatment.

**✓ Correct Answer: D. T4 is any size**