Anew object, object z, was discovered outside our solar system. object z is made of frozen gases that surround a rocky core and it travels in a highly elliptical orbit around the sun. the characteristics of object z most closely resemble those of other

Considering; multiple choices;
Asteroids, dwarf planets, comets, and moons
The best answer is Comets
Comets are cosmic snowballs of frozen gases, rock and dust roughly the size of a small town. Unlike asteroids which are generally comprised of rock and metal, comets are more akin to dirty snowballs. They are composed of frozen gases such as carbon dioxide, methane, and ammonia, as well as water ice, in which dust particles and rocky material are embedded. 

D. peatlands,grassland,swamps

Icant be totally sure but i would say with confidence that it is example #1 about cells.