Okok i think it is 2 but like i might be wrong so dont get mad at me if its wrong
Answer:
Earth (From order to crust to inner core)
Crust
Mantle
Outer Core
Inner Core <----Most inner layer
Here is the answer that would best complete the given statement above. Specialized cells in plant roots ensure that they grow down into the soil to find water and nutrients. This plant response by specialized cells is calledGRAVITROPISM. This is also known as geotropism wherein plants grow in response to gravity. Hope this answer helps.
Because you need your legs to carry your whole body, so, essentially, your legs have to have bigger bones and muscles.