In comparison to boron, berylium has

The correct option is D lesser nuclear charge and greater first ionisation enthalpy
In comparision to boron, beryllium has lesser nuclear charge and greater first ionisation enthalpy.
Electronic configuration of $Be\left(4\right)=1s^2,2s^2$
It possess completely filled $s-$ orbital. Hence, high amount of energy is required to pull the electron from the gaseous atom. Beryllium (4) lies left of the boron (5) and on moving from left to right a proton is added due to which nuclear charge increases from $Be$ to $B$.