Flowering plants are the most successful land plants. this is due, in part, to the trait that could be the label for point
c. in the cladogram. what trait is unique to this group of plants?
a. vascular tissue
b. perennial growth
c. seeds protected in fruits
d. alternation of generations

c.seeds protected in fruits        

All flowering plants belong to the group of angiosperms. These plants exhibit true roots, stems and leaves. The ovary in these plants are enclosed in a flower and the fertilized ovules develop into seeds which are covered and preserved inside a fruit develop from other parts of the flower. This trait is unique in the group of flowering plants.

trachea, alveoli, lung capillaries, arteries

the corpus luteum secretes estrogens and progesterone. the latter hormone causes changes in the uterus that make it more suitable for implantation of the fertilized ovum and the nourishment of the embryo. if the egg is not fertilized, the corpus luteum becomes inactive after 10–14 days, and menstruation occurs.

i hope this : )