The scientific name for a white oak is quercus alba; the scientific name for a red oak is quercus rubra. what does this tell you about the organism?

a. red oaks are grouped in the genus alba.
b. white oaks are grouped in the genus quercus.
c. white oaks are grouped in the same species category as red oaks.
d. red oaks are grouped in the species quercus.

is it

The answer is B. White oaks are grouped in the genus Quercus. 

According to binomial nomenclature, a formal system of naming species, a name of species is composed of two parts. The first word indicates the organism's genus classification, the second word indicates the species within a genus. So, the first word Quercus indicates the genus in both cases, the second word alba or rubra indicates species within the genus Quercus.

A. is not the right answer because alba indicates species name, not genus name.
C. is not the right answer because white oaks and red oaks are different species, but the same genus.
D. is not the right answer because Quercus is not species but genus.