Which tree species is characterized by leaves with four lobes separated by rounded notches, a waxy and smooth texture, and greenish-yellow, tulip-like flowers that appear in mid-spring?

a) Yellow Poplar (Liriodendron tulipifera)
b) Red Maple (Acer rubrum)
c) White Birch (Betula papyrifera)
d) Sweetgum (Liquidambar styraciflua)