Scientists Use Existing Fossils to Predict What the Transitional Forms

Scientists use existing fossils to predict what the transitional forms between organisms might look like. Why is it so hard for scientists to find fossils of these transitional forms?

A) Scientists have no way to determine how deep in a rock to look for a transitional fossil, so they just have to dig and dig until they find the right fossil.
B) Because of continental drift, the exact location of where a transitional fossil should be found cannot be determined. Looking for a particular fossil that could be anywhere on the planet is like looking for a needle in a haystack.
C) Fossils of transitional species may have never formed due to environmental conditions, or if they did form, natural processes like erosion may have destroyed them.
D) The transitional form of any organism is only hypothetical in nature; it never truly existed on the planet and, therefore, could never become a fossil.