Missing Synthetic backup option

We have two full-timers here and both of us are a bit new, so I've been tasked with getting up to speed on our backup system(s). We are running BE 15, and I'm trying to determine if our backup schedule is meeting our needs. Ages ago, I would have set up a system of monthly backups with weekly differentials and daily incrementals. But this was when tapes were the thing, and our current systems now use disk-based backups. So, basically, we do a full backup every three months, and then just daily incrementals until the next full backup. 

Am I correct in assuming that if we needed to restore data to the server, BE would see this as one large job and would mount the media it needed and retrieve the data? I see the Advanced Disk-based Backup option in Backup Options where it will allow me to "Use offhost backup," but what concerns me is that I don't see the Synthetic job option available when I go to create a new backup job. Does this mean that we don't have the Enterprise Server Option installed? Since we have the ADBO option available, I thought that meant we do, but I don't see it in Licensing. 

We also have a Dell AppAssure product, which looks to be our option for any bare-metal restores we might have to do. One thing at a time, though, just dealing with BE right now. Thanks.