Navigate to WHMCS System Settings >> Configurable Options
Find for Vmware Resources and click on Edit icon.
Find for ram, cpu, hardisk and click on Edit icon one by one.
A popup will be opened. Change Option Type: from Quantity to Dropdown and click on Save Changes
After that enter the option values as given below.
RAM: Add options like 1|1GB, 5|5GB, 10|10 GB.
CPU Add options like 1|1 Core, 4|4 Cores, 10|10 Cores.
Disk: Add options like 10|10GB, 50|50GB, 100|100 GB.
Note Enter one option and Save Changes then add new option. Don't put all options like this 1|1GB, 5|5GB, 10|10 GB
It will look like below given screenshot.
