Solutions
LM-C09-C-001
An embedding matrix has one row per token id, so it has 12,000 rows.
LM-C09-C-002
One token id selects one embedding row.
LM-C09-C-003
The example contrasts two meanings: river side and financial institution.
LM-C09-C-004
A list of 10 nearest neighbors contains 10 inspected entries.
LM-C09-C-005
No. Nearest neighbors are useful clues about learned geometry, not proof of exact meaning.