Answer:
Layer A: inner core
Explanation:
The solid, inner core (Layer A) is comprised mainly of iron and nickel and is scorching hot. The outer core (Layer B) does have iron and nickel as well, but it's in its liquid form. The lower mantle (Layer C) consists of iron-rich perovskite, which is a ferromagnesian silicate mineral. The upper mantle (Layer D) is made of olivine, pyroxene, calcium oxide, and aluminum oxide.
Answer:

Explanation:
C4 plants incorporate carbon dioxide into malate, a four-carbon compound, before it enters the Calvin cycle. C4 plants sequester RuBisCO and the Calvin cycle enzymes in the leaf bundle sheath cells, while RuBisCO occurs throughout the mesophyll of C3 leaves.
When the concentration of the solute is lower inside the cell than outside it
--To pump a molecule across a membrane against its concentration gradient, the cell must expend metabolic energy, which is provided by ATP. This type of membrane traffic is called active transport.--