b
\(_1{{\text{H}}^2}{ + _1}{{\text{H}}^2}{ \to _2}{\text{H}}{{\text{e}}^4} + \Delta E\)

The binding energy per nucleon of a deuteron \(=1.1 \mathrm{\,MeV}\)

\(\therefore\) Total binding energy \(=2 \times 1.1=2.2 \mathrm{\,MeV}\)

The binding energy per nucleon of a helium nuclei \(=7 \mathrm{\,MeV}\)

\(\therefore\) Total binding energy \(=4 \times 7=28 \mathrm{\,MeV}\)

Hence, energy released

\(\Delta E=(28-2 \times 2.2)=23.6\,MeV\)