What is known scientifically about transitional forms in the fossil record? Group of answer choices
a. They conclusively provide the genetic linkage between Coke and Pepsi.
b. They are not observed.
c. They are found frequently for those general types of living things (such as shelly shallow-marine creatures) that commonly produce fossils, but are not found as frequently for other general types
d. They provide complete records of every fossil lineage.