Two electron(s) are removed from an carbon atom. Enter the chemical symbol of the element.

Explanation:

When a proton is removed, it changes the whole element. However, when electrons are removed, it becomes an ion. Since we are removing two electrons, we are subtracting a negative number, giving us positive two as our net ionic charge. Therefore, the answer is

it can be icreased by increasing pressure.

i think it's c. i'm not sure but i think so.