Because he temper and and doesn’t want to show weakness
There are 2 options:
1) get the normal amount of sleep (7-9 hours) with some naps during the day.
2) Take a few more hours of sleep along with your 7-9 hours.
It's got to be C because none of the others relate to collaboration, but I'd say if you were unsure about this answer then the only other sensible one could be B, but I'd go with C.
C. hers is the singular pronoun
Asteroids offer a source of volatiles and an extraordinarily rich supply of minerals that can be exploited for the exploration and colonization of our solar system in the twenty-first century. Asteroids represent the bits and pieces left over from the process that formed the inner planets, including Earth.
