Fair warning:
-You should definitely back up this VM before proceeding.
-It's best to practice this on a testing VM with the same OS to verify it'll work.
-You might end up having to reboot anyway.
Check out http://blog.pluralsight.com/resize-vmware-linux-drives assuming you're using RHEL.
One thing I've found is that sometimes fdisk does not correctly report the increased size of the disk, but cfdisk will. So if you did this to SDC, try:
sudo cfdisk /dev/sdc
and see if your extra space shows up there.
Good luck!