The correct answer is 3. The TNM system is a widely used cancer staging system that provides a standardized way to describe the extent of cancer in a patient's body. TNM system stands for:

T - Tumor: This component describes the size of the primary tumor and how far it has grown into nearby tissues. It is typically categorized as T0, Tis (in situ), or a range of numerical values (e.g., T1, T2, T3, T4) indicating increasing tumor size and extent of invasion.

N - Nodes: This component indicates whether cancer has spread to nearby lymph nodes and how many lymph nodes are affected. It is categorized as N0 (no spread to lymph nodes), N1, N2, N3, etc., indicating an increasing extent of lymph node involvement.

M - Metastasis: This component indicates whether the cancer has spread to distant parts of the body, beyond the primary site and nearby lymph nodes. It is categorized as M0 (no distant metastasis) or M1 (distant metastasis present).

The TNM information is combined to determine the overall cancer stage, which is often expressed as a numerical stage (Stage 0, I, II, III, or IV) or as descriptive terms such as early-stage, locally advanced, or metastatic. The stages reflect the extent of the cancer and help guide treatment decisions.