ValueRenderOption

Determines how values should be rendered in the output.

Enums
FORMATTED_VALUE Values will be calculated & formatted in the reply according to the cell's formatting. Formatting is based on the spreadsheet's locale, not the requesting user's locale. For example, if A1 is 1.23 and A2 is =A1 and formatted as currency, then A2 would return "$1.23".
UNFORMATTED_VALUE Values will be calculated, but not formatted in the reply. For example, if A1 is 1.23 and A2 is =A1 and formatted as currency, then A2 would return the number 1.23.
FORMULA Values will not be calculated. The reply will include the formulas. For example, if A1 is 1.23 and A2 is =A1 and formatted as currency, then A2 would return "=A1".