Data replication is the technique that introduces redundant copies of data. It can help horizontally scale read capacity, but it also increase data durability and availability. Replication can take place in a few different modes.
You want to use replicas to horizontally scale the system’s data storage but you cannot tolerate any replication lag. Which type of repliaction should you use?
That was the correct answer, well done! 
Sorry, that was the wrong answer 