auth-source-read-char-choice
auth-source-read-char-choice is a compiled Lisp function in `auth-source.el
'.
(auth-source-read-char-choice PROMPT CHOICES)
Read one of CHOICES by `read-char-choice', or `read-char'.
`dropdown-list' support is disabled because it doesn't work reliably.
Only one of CHOICES will be returned. The PROMPT is augmented
with "[a/b/c] " if CHOICES is '(?a ?b ?c).