Answer:
The correct option is: A. carbon-12
Explanation:
The CNO cycle, the abbreviation for the carbon-nitrogen-oxygen cycle, is a catalytic cycle by which the stars produce helium from elemental hydrogen, via a series of nuclear fusion reactions.
This cycle involves the fusion of four protons with carbon (), nitrogen isotope (
), and oxygen isotope (
), to give an alpha particle and two electron neutrinos and positrons.
The reaction involves the regeneration of carbon () nucleus in the last step.
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