c
\({ }^4 \mathrm{He}+{ }^4 \mathrm{He}+{ }^4 \mathrm{He} \rightarrow{ }^{12} \mathrm{C}+\mathrm{Q}\)

\(\text { power generated }=\frac{\mathrm{N}}{\mathrm{t}} \mathrm{Q}\)

\(\text { where, } \mathrm{N} \rightarrow \text { No. of reaction/sec. }\)

\(\mathrm{Q}=\left(3 \mathrm{~m}_{\mathrm{He}}-\mathrm{m}_{\mathrm{C}}\right) \mathrm{C}^2\)

\(\mathrm{Q}=(3 \times 4.0026-12)\left(3 \times 10^5\right)^2\)

\(\mathrm{Q}=7.266 \mathrm{MeV}\)

\(\frac{\mathrm{N}}{\mathrm{t}}=\frac{\text { power }}{\mathrm{Q}}=\frac{5.808 \times 10^{30}}{7.266 \times 10^6 \times 1.6 \times 10^{-19}}\)

\(\frac{\mathrm{N}}{\mathrm{t}}=5 \times 10^{42}\)

rate of conversion of \({ }^4 \mathrm{He}\) into \({ }^{12} \mathrm{C}=15 \times 10^{42}\)

Hence, \(n=15\)