(b)if the capital asset became the property of the assessee by any of the modes specified in section 73 (Table: Sl. No. 1), and the capital asset became the property of the previous owner before the 1st April, 2001, subject to sub-section (10), shall be the cost of the capital asset to the previous owner or its fair market value on the 1st April, 2001, at the option of the assessee;