No option for "Copy to clipboard on selection".

What is the output of:

lsb_release -a; uname -a; apt-cache policy xfce4-terminal

Thanks

$ lsb_release -a
LSB Version: 1.4
Distributor ID: Arch
Description: Arch Linux
Release: rolling
Codename: n/a

$ uname -a
Linux hostname 4.8.4-1-ARCH #1 SMP PREEMPT Sat Oct 22 18:26:57 CEST 2016 x86_64 GNU/Linux

$ pacman -Qiiv xfce4-terminal
Root : /
Conf File : /etc/pacman.conf
DB Path : /var/lib/pacman/
Cache Dirs: /var/cache/pacman/pkg/
Hook Dirs : /usr/share/libalpm/hooks/ /etc/pacman.d/hooks/
Lock File : /var/lib/pacman/db.lck
Log File : /var/log/pacman.log
GPG Dir : /etc/pacman.d/gnupg/
Targets : xfce4-terminal
Name : xfce4-terminal
Version : 0.8.0-2
Description : A modern terminal emulator primarly for the Xfce desktop environment
Architecture : x86_64
URL : http://www.xfce.org/
Licenses : GPL2
Groups : xfce4
Provides : None
Depends On : libxfce4ui vte3 hicolor-icon-theme
Optional Deps : None
Required By : None
Optional For : None
Conflicts With : terminal
Replaces : terminal
Installed Size : 1566,00 KiB
Packager : Evangelos Foutras <email address hidden>
Build Date : 2016-10-18T23:29:54 +10
Install Date : 2016-10-19T10:30:06 +10
Install Reason : Explicitly installed
Install Script : No
Validated By : Signature
Backup Files :
(none)

This is Ubuntu support only. You are using Arch which is not supported here. Each distribution has its own support forum and community

I suggest you post here
https://bbs.archlinux.org