<prompt> Lymphatic drainage of the outer upper quadrant of the breast is mainly to:Anterior axillary groupInternal mammary groupPosterior axillary groupApical nodes  <response>: Ans: a Anterior axillary nodes Ref: BDC Vol. I, 4th ed, p. 42About 75 of the lymphatics from the breast drain into the axillary nodes. Among the axillary nodes, the lymphatics mostly end in the anterior group pectoral group, closely related to the axillary tail of the breast. 