Another name for the hole in which the eye sits in the skull is
a. sclera.
c. orbit
b. pupil.
d. mandible

First, look at your choices and eliminate the ones that obviously don't fit.
So a mandible (jaw) and a pupil (one the eye) don't work
Out of the two left..
A sclera won't work since it of apart of the eye.
So you only have orbit left.
By definition, orbit is the answer you are looking for.

Hope this helped! :)

C. Orbit, or eye socket. This is the bony structure that surrounds the soft tissue around the eye to form a kind of protection

Mg is used to measure mass

It would be c. because they are the same species. the definition for genus is a principal taxonomic category that ranks above species and below family, and is denoted by a capitalized latin name