The geologic period during which most of the life forms which ultimately became the "fossil fuels" lived is the . Question 2 options: Carboniferous Pleistocene Cambrian Cretaceous

Cretaceous

Explanation:

    The Cretaceous is the last period of the Mesozoic era, located between 145 and 65 million years ago.

    In the Cretaceous, the Earth begins to take the shape we know today. Whitish rocks appear that characterized the strong incidence of limestone in this period.

    In the middle of the Cretaceous, the formation of more than 50% of the world oil reserves that are known today began, of which the concentrations located around the Persian Gulf and in the region between the Gulf of Mexico and the coast of Venezuela.