During Surgery for Breast Cancer, Surgeons Will Often Remove Lymph

During surgery for breast cancer, surgeons will often remove lymph nodes in the armpit. What is the most likely reason for this?

A) If any cancer cells have entered the lymph, they will travel to the closest lymph nodes, which are in the armpit.
B) Lymph nodes in the armpit are responsible for breast cancer.
C) Lymph nodes that are close to the surgical incision would prevent healing following the surgery.
D) Lymph nodes in the armpit become useless because of the surgery and can be removed without problem.
E) Lymph nodes do not help a person and are better removed before they become infected.