Answer: A) Accretion
Explanation:-
Accretion is the accumulation of particles into a large object caused by gravitation.Most galaxies, stars, and planets are formed by accretion process.
Photosynthesis is a phenomenon in which green plants containing chlorophyll use sunlight as a source of energy to convert carbon dioxide and water to form glucose and oxygen.
Equilibrium is a reversible chemical reaction in which rate of forward reaction is equal to the rate of backward reaction.
The concentration of the reactants and products remain constant.
Nuclear fusion is a process which involves the conversion of two small nuclei to form a heavy nuclei along with release of energy.
