Correct Answer: CTo determine the usable space after enabling Erasure Coding (EC) on a 5-node cluster with an RF2 configuration and 200 TB of raw disk space, we need to consider how EC impacts the efficiency. With RF2, each piece of data is replicated twice, using up a significant portion of the raw space. By enabling EC, we distribute data and parity information across the nodes, typically converting to something like a 3:2 data to storage ratio for actual data vs. parity. This results in approximately 150 TB of usable space because 3/4th of the raw disk space will now be utilized for actual data. Therefore, the approximate usable space after enabling Erasure Coding will be 150 TB.