140. A taxpayer may deduct in computing the taxpayer’s income for a taxation year, as a reserve, the aggregate of(a) a reasonable amount in respect of doubtful debts, other than a debt in respect of which paragraph b applies, that have been included in computing the taxpayer’s income for the year or a preceding taxation year, and
(b) where the taxpayer is a financial institution, within the meaning of section 851.22.1, in the year or a taxpayer whose ordinary business includes the lending of money, an amount not exceeding the particular amount determined for the year under section 140.1 in respect of properties, other than mark-to-market properties, as defined in the first paragraph of that section 851.22.1, that are impaired loans or lending assets that are specified debt obligations, as defined in that paragraph, of the taxpayer, or impaired loans or lending assets that were made or acquired by the taxpayer in the ordinary course of the taxpayer’s business of insurance or the lending of money.