You write a stored procedure that will return data for a report. The accuracy of the data is not so important; however, you want to avoid dirty reads. Which isolation level should you avoid?

Read Uncommitted isolation level allows dirty reads, meaning it can read data that has been modified but not committed by other transactions. Since the requirement is to avoid dirty reads, Read Uncommitted must be avoided. Read Committed, Repeatable Read, and Serializable all prevent dirty reads by only reading committed data.