Window Design Strategies Heating Climate

What are the energy efficiency design strategies for a building in heating-dominated climate for energy efficiency? (circle all that apply)

(a). Increase window size on the north façade while maintaining the same overall building window ratio

(b). Increase window size on the south façade while maintaining the same overall building window ratio

(c). Build an overhang above windows on the north façade

(d). Build an overhang above windows on the south façade

(e). Install low-E windows on the south façade only

(f). Install low-E windows on all  facades