Assertion (A) : The bond energy of ${\text{H}}_2$molecule is greater than HCl molecule.

Reason (R) : The bond energy in the overlapping between $1s$ and $1s$sub shells of ${\text{H}}_2$is greater than that of $3p$ and sub shells of HCl.

The bond energy of ${\text{H}}_2$molecule is greater than HCl molecule.  Due to s-orbital’s two hydrogen atoms is close to the nucleus then the bond length is low.  But p-orbital of chlorine far to the nucleus then the bond length is high in HCl.  So the bond energy of  ${\text{H}}_2$ is greater than HCl.