The binding energy per nucleon $v/s$ mass number curve for nuclei is shown in the figure. $w, x, y$ and $z$ are four nuclei indicated on the curve. The process that would release energy is:

Given below are two statements:
Statement $I$: For all elements,greater the mass of the nucleus,greater is the binding energy per nucleon.
Statement $II$: For all elements,nuclei with less binding energy per nucleon transform to nuclei with greater binding energy per nucleon.
In the light of the above statements,choose the correct answer from the options given below:

Binding energy per nucleon of a fixed nucleus $X^A$ is $8 \ MeV$. It absorbs a neutron moving with kinetic energy $2 \ MeV$ and converts into $Y$,emitting two photons of energy $1 \ MeV$ and $4 \ MeV$ respectively one after the other. The binding energy per nucleon of $Y$ (in $MeV$) is:

The binding energy per nucleon of ${ }_{8}^{16}O$ is $7.97 \text{ MeV}$ and that of ${ }_{8}^{17}O$ is $7.75 \text{ MeV}$. The energy required to remove one neutron from ${ }_{8}^{17}O$ is $\qquad \text{ MeV}$.

$A$ nuclide $1$ is said to be the mirror isobar of nuclide $2$ if $Z_1 = N_2$ and $Z_2 = N_1$. $(a)$ What nuclide is a mirror isobar of $_{11}^{23}Na$? $(b)$ Which nuclide out of the two mirror isobars has greater binding energy and why?

Mass numbers of the elements $A, B, C$ and $D$ are $30, 60, 90$ and $120$ respectively. The specific binding energies of them are $5 \text{ MeV}, 8.5 \text{ MeV}, 8 \text{ MeV}$ and $7 \text{ MeV}$ respectively. In which of the following reaction$(s)$ is energy released?
$1. D \rightarrow 2B$
$2. C \rightarrow B + A$
$3. B \rightarrow 2A$