Which of the following is a true statement?

a. falling sea levels and colliding continents created connections between continents that led to great movements of land animals during the neogene period.
b. during the quarternary period, the earth heated up.
c. the first whales evolved during the quarternary period
.d. land mammals such as bats, cats, dogs, cattle and mammoths became common during the neogene period.

For B,the Quarternary Period is more commonly known as the ice age, so that wouldn't be the answer.
For C, the first whales evolved 15 million to 50 million years ago, and the Quartenary Period was only around 1.8 million years ago, so that eliminates that answer as well.
For D, the Neogene Period gave rise to early primates such as early humans, sheep, goats, and gazelle flourished in this period. The bats, cats, dogs,  cattle and mammoths cam more in the Quartenary period. 
Therefore by process of elimination, A should be the correct answer.

Falling sea levels and colliding continents created connections between North and South America, and between Africa, Europe, and Asia. Those connections led to great movements of land ani- mals between continents.

D.) domain, kingdom, phylum, class, order, family, genus, species