I believe it would be A.) The creation of atomic nuclei!
The distance of Earth from the Sun is 94.5 million miles.
A light year is 6 trillion miles so it would be less.*
Answer:
Active uptake (which I think you mean active transport) is important when the concentration gradient is against that of a certain substance, so it doesn't cross the membrane through diffusion or passive transport. It is sometimes necessary if a substance needs to move across a membrane but can't do so due to electrical charge or that there is a substance on the other side of the membrane preventing diffusion.
Explanation: