The diagram shows a football field that represents a geological time scale.

why are no organisms labeled between the end zone and 30 yard line on the left side of the field?

scientists disagree about the fossils from this time period.
scientists have not studied that part of the time scale.
there is very little fossil evidence for this time period.
there are too many fossils to name.

Option B

Explanation:

The formal study of fossils, its collection and documentation started in 1700s during the period known as “Age of Enlightenment” It was during this time period that scientist noticed rock fossils and started making fossil collection. During the 1800s, areas with  rocks fossils were studied and compared.  

Further,  Charles Lyell and Charles Darwin showed strong connection between biological evolution and geological evolution of planet earth. Hence, the earlier traces of fossils i.e before a certain period could not be studies due to late pioneering of fossil based evolutionary science. It is also due to limitations with radioactive dating

Hence, option B is correct