Final answer:
The alkali metals have the lowest first ionization energies among the listed groups.
Step-by-step explanation:
The elements with the lowest first ionization energies among the groups listed are the alkali metals. The alkali metals, which belong to Group 1 of the periodic table, have low ionization energies because they have only one valence electron, which is not strongly held by the nucleus. This makes it easier for alkali metals to lose their outermost electron and form a positively charged ion.