Final answer:
The more metallic elements can be determined by their positions in the periodic table.
Step-by-step explanation:
On the basis of periodic trends, the more metallic element can be determined by looking at the elements' positions in the periodic table. Metallic character tends to increase as you move from right to left and from top to bottom in the periodic table.
For Part A, Ge is located to the left of Sn in the periodic table, so Ge is more metallic than Sn.
For Part B, Sb is located to the left of Po, so Sb is more metallic than Po.
For Part C, Cl is located to the left of I, so Cl is more metallic than I.
For Part D, B is located to the left of N, so B is more metallic than N.