Question: Which two characteristics define Amazon Quantum Ledger Database?

1. Key-value data model; transactionally consistent with ACID semantics.
2. Document data model; transactionally consistent with ACID semantics.
3. Key-value data model; transactions with tunable consistency.
4. Document data model; transactions with tunable consistency.

Answer: The correct answer of the above question is Option B:Document data model; transactionally consistent with ACID semantics.