Hellpp with this ill give brainliest

Which element forms the basis of all organic organisms a carbon b oxygen c hydrogen d nitrogen

Which best describes the nucleus of an atom a. it is where all of the particle s of the atom are located b. it is the negatively charged part of the atom c. it is where the electrons and the protons are located d. it is the part of the atom with the greatest mass

How can we use spectral lines of light coming from the superclusters to identify which is receding from earth at the slowest rate.