Article 1873-14 of the French Civil Code
The option to acquire or allocate lapses if its beneficiary has not exercised it by notifying the surviving undivided co-owners and the heirs of the predeceased within one month of the day on which he was given formal notice to take a decision. This formal notice may not itself take place before the expiry of the period provided for in the title “Inheritances” for making an inventory and deliberating. Where…