/usr/lib/x86_64-linux-gnu/libopts.so is in libopts25-dev 1:5.18-2ubuntu2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libopts.so.25.15.0
/usr/lib/x86_64-linux-gnu/libopts.so.25.15.0