Which Statement About Transitional Features Is True

Which statement about transitional features is true?

A) Hemoglobin expression transitions from the fetus to newborn due to the requirement of hemoglobin in the fetus to be able to bind oxygen more tightly.
B) Transitional features show that natural selection sometimes plans ahead to achieve evolutionary goals in a species.
C) A bird's wing and a bat's wing are examples of transitional features.
D) Fossil species with transitional features are not necessarily direct ancestors of living species, but they are likely closely related to the ancestor.
E) Scientists have not yet discovered any examples of true transitional features.