[Q7] Genome rearrangements: weighted median

For a given adjacency α to appear in the weighted median of n genomes, and assuming that all of them have the same weight, it is required for α to be present in:

1. All genomes
2. At least n - 1 genomes.
3. At least the half of the genomes.
4. At least one more genome than their conflicting adjacencies.
5. None of the above.

Original idea by: Juan Felipe Hernández Albarracín.