We decided on a new policy based on the survey results.
Standard kanji spelling using 基 (foundation/basis).
Alternate spelling using 元 (origin/source). Both are used, but 基 is more common for 'based on'.
A compound of the particle を, the noun 基 (もと, 'basis' or 'foundation'), and the verb する in its て-form (として). Literally 'taking as a basis'.