I think it would depend on how many different "reasons" tables you will have.
If all your "reasons" could go into a single table, then I would opt for A.
That way the field you labeled "value" really could change to
reason_id FK reasons(reason_id)
And I would see nothing wrong with also having an
additional_info smalltext field for those occasions where one of the pre-canned reasons doesn't fit or isn't descriptive enough.
An optimist sees the glass as half full.
A pessimist sees the glass as half empty.
A realist drinks it no matter how much there is.