Which elements are most likely in the same periods of the periodic table?

A table with 5 columns and 5 rows labeled facts about 4 elements. The first column labeled element has entries aluminum (A l), boron (B), carbon (C), gallium (G a), germanium (G e). The second column labeled atomic mass (a m u) has entries 27, 11, 12, 70, 73. The third column labeled total electrons has entries 13, 5, 6, 31, 32. The fourth column labeled valence electrons has entries 3, 3, 4, 3, 4. The fifth column labeled year isolated has entries 1825, 1808, 1803, 1875, 1886.

Boron and carbon are likely together in one period because they have very close atomic numbers, while gallium and germanium are likely together in another period because they have very close atomic numbers.
Aluminum, boron, and carbon are likely together in one period because they were first isolated in the first half of the 1800s, while gallium and germanium are likely together in another period because they were first isolated in the second half.
Boron and carbon are likely together in one period because they each end in “-on,” while aluminum, gallium, and germanium are likely together in another period because they each end in “-ium.”
Aluminum, boron, and gallium are likely together in one group because they have the same number of valence electrons, and carbon and germanium are likely together in another group because they have the same number of valence electrons.