Answer: The correct answer is Option C.
Step-by-step explanation:
Nuclear fusion reaction is defined as the reaction in which two lighter nuclei join (fuses) together to form a heavier nuclei.
Number of protons determine the atomic number of an element.
The chemical reaction representing the nuclear fusion of nitrogen and hydrogen is given by the equation:

The fusion of these two elements results in the formation of oxygen atom which has 8 protons.
Thus, the correct answer is Option C.