Which of the following observations constituted the strongest evidence against the existence of blending inheritance?
a) Some characters are shaped by the environment (as well as heredity).
b) Sometimes two parents have the same appearance, but they have one or more offspring with a different appearance.
c) Characters acquired from the environment of the parents are often transmitted to the offspring.
d) Individuals never have characters intermediate to their parents-- there is always complete "dominance" of one parent's character.