Best variable: z. Unique, distinctive, commonly used in math/science, and the correct option is A.
The image shows a text question about choosing a variable to represent the number of wallabies in an exhibit. The text provides four possible variables and asks the reader to explain which one is the best choice.
The four possible variables are:
z = the number of wallabies in the exhibit
a the number of wallabies in the exhibit
z = the number of wallabies in the exhibit
the number of wallabies in the exhibit
The best choice for a variable to represent the number of wallabies in an exhibit is z.
The letter z is commonly used in mathematics and science to represent an unknown variable. It is also a unique and distinctive letter, which makes it easy to read and write.
The other possible variables are not as good of a choice. The letter a is already commonly used to represent other variables, such as the area of a triangle or the acceleration of an object. The phrase "the number of wallabies in the exhibit" is too long and cumbersome to use as a variable.
Therefore, the correct option is A.