Exam 70-487 topic 1 question 4 discussion

I think the choice is between ReadCommitted and Repeatable. RepeatableRead also prevents the application from reading data that is locked by other transactions. In addition it does not use exclusive range locks as Serializable does. The advantage of using RepeatableRead instead of ReadCommitted is that RepeatableRead has a higher consistency, because it avoids nonrepeatable reads. However this could be a tricky question, since the question uses the phrase Repeatable and not RepeatableRead, but that would be very childish thing to do.

Objective 1.3. ReadCommitted: Shared locks are held during reads. This has the result of avoiding dirty reads, unlike ReadUncommitted. However, the data can be changed before the end of the transaction, resulting in nonrepeatable reads or phantom data.

Can't use serializable as one of the requirement is not to use exclusive range locks

https://docs.microsoft.com/en-us/dotnet/api/system.transactions.isolationlevel?view=netframework-4.8