How should the administrator resolve this problem?

Refer to the Exhibit.

An administrator wants to increase the capacity of a VMFS5 datastore; but the Increase Size by slider is not available, as shown in the Exhibit.
How should the administrator resolve this problem?
A. Select a valid partition configuration from the drop-down menu.
B. Use fdisk utility to manually resize the partition.
C. Use the mouse to resize the partition indicated in the Partition Layout.
D. Clicking Next will prompt for available usable space.