Phản ứng nào sau đây là phản ứng phân hạch?

${}_1^2\text{H}+{}_1^2\text{H}\to {}_2^4\text{H}\text{e}$.

${}_0^1\text{n}+{}_{92}^{235}\text{U}\to {}_{39}^{95}\text{Y}+{}_{53}^{138}\text{I}+3{}_0^1\text{n}$.

${}_1^2\text{H}+{}_1^3\text{H}\to {}_2^4\text{H}\text{e}+{}_0^1\text{n}$.

${}_{84}^{210}\text{P}\text{o}\to {}_{82}^{206} \text{P}\text{b}+{}_2^4\text{H}\text{e}$.