What is a possible reason for the storage usage level?

A systems administrator has an Isilon cluster with three X410 nodes in their environment. The default protection setting is 2d:1n at the node pool level. Billions of very small image files, less than 50 KB size, are stored on the cluster.

Recently, the administrator has seen an issue where the cluster’s used capacity is getting full. However, the cumulative size of the files copied appears to be less.

What is a possible reason for the storage usage level?
A . Small files are stored with 4x mirror protection and consuming more capacity
B . Small files are stored with 2x mirror protection and consuming more capacity
C . Metadata of billions of files is consuming most of the capacity
D . Small files are spread across all nodes and consuming more capacity

Answer: B