What are the “power lines” of the body that send messages back and forth between the brain and all the other tissues and organs?

A) bone marrow cells
B) nerves
C) joints
D) muscles

Ruth is 44 years old. at her medical checkup, her doctor notices that ruth's lymph nodes are enlarged. after some blood tests and a ct scan, ruth's doctor diagnoses her with ( ) , a cancer that typically starts in the lymphocytes and can spread to the bone marrow.