Which of the mechanisms below increases the amount of genetic variations in a population?

Although the two theories differ on the evolutionary path of dinosaurs, they agree that

One important development during the 3rd trimester that will insulate the infant against changes in temperature is a. the deposition of fat under the skin b. the closing of the septum between c. the atria of the heart d. the beginnings of lung functioning e. the beginnings of light and sound sensing

Which two criteria must be met before scientist can use radiocarbon dating? explain your answer