A.  In the case of any loss claimed to have been sustained from any sale or other disposition of shares of stock or securities where it appears that, within a period beginning thirty days before the date of such sale or disposition and ending thirty days after such date, the taxpayer has acquired (by purchase or by an exchange upon which the entire amount of gain or loss was recognized by law), or has entered into a contract or option so to acquire, substantially identical stock or securities, then no deduction for the loss shall be allowed under La. Rev. Stat. 47:60(2); nor shall such deduction be allowed under La. Rev. Stat. 47:61, unless the claim is made by a corporation, a dealer in stocks or securities, and with respect to transactions made in the ordinary course of its business.  

B.  If the amount of stock or securities acquired (or covered by the contract or option to acquire) is less than the amount of stock or securities sold or otherwise disposed of, then the particular shares of stock or securities the loss from the sale or other disposition of which is not deductible shall be determined under rules and regulations prescribed by the collector.  

C.  If the amount of stock or securities acquired (or covered by the contract or option to acquire) is not less than the amount of stock or securities sold or otherwise disposed of, then the particular shares of stock or securities the acquisition of which (or the contract or option to acquire which) resulted in the nondeductibility of the loss, shall be determined under the rules and regulations prescribed by the collector.