If a molecule is reduced it gains:

Explanation

When a molecule undergoes reduction, it gains electrons, hydrogen/protons, and often energy. The process of reduction is fundamental in many biological processes, including cellular respiration, photosynthesis, and various metabolic pathways. Redox reactions play a central role in transferring energy and driving chemical reactions in living organisms. In summary, option d) "all of the above" is the correct answer because reduction involves the gain of electrons and hydrogen/protons, and often results in the acquisition of energy by the molecule undergoing the reduction reaction.