(1)[Where an assessee incurs any expenditure] [Substituted by Act 12 of 1990, Section 12, for sub-Section (1) (w.e.f. 1.4.1991).] [on or before the 31st day of March, 2002] [ Inserted by Act 12 of 1990, Section 12 (w.e.f. 1.4.1991).][by way of payment of any sum-(a)to an association or institution, which has as its object the undertaking of any programme of conservation of natural resources or of afforestation, to be used for carrying out any programme of conservation of natural resources or afforestation approved by the prescribed authority; or(b)to such fund for afforestation as may be notified by the Central Government, the assessee shall, subject to the provisions of sub-section (2), be allowed a deduction of the amount of such expenditure incurred during the previous year.