As one moves along a given row in the periodic table,ionization energy

Which of the following isoelectronic ions has the lowest ionization energy?

Assertion $(A)$: Boron has a smaller first ionisation enthalpy than beryllium.
Reason $(R)$: The penetration of a $2s$-electron to the nucleus is more than the $2p$-electron; hence,the $2p$-electron is more shielded by the inner core of electrons than $2s$-electrons.

The first ionisation energies of alkaline earth metals are higher than those of the alkali metals. This is because

Which particle may be removed from a stable neutral atom with the least energy change?

Which of the following sets has the highest sum of $IE$ values compared to all other sets mentioned?