Apparently when a dash aka minus sign is used as the first character of a text field, a single quote is inserted in CSV export. There's no need for this and it confusing when you expect a normal CSV export behaviour.
Can you please list the extra character insertions you do beyond what the CSV format requires?
EDIT: it's inconsistent even. Sometimes it inserts a single quote (that isn't there in the data) and sometimes it doesn't. Even two rows below each other.
% grep -o '..\- C[^ ]\+' exported.csv
,"- Choice
"'- Choice
After experimentation, we found that a single quote is inserted at the start of the value if:
- The value starts with a dash
- The value contains an opening round bracket (aka parenthesis)
This sounds like a bug rather then a feature to me.