Addition of section 54D expands capital gains exemption linkage under Section 45 of the Income tax Act. Amendment adds section 54D to the list of provisions referenced in Section 45 of the Income tax Act, replacing the prior cross references 'sections 53, 54, 54B, 54C' with 'sections 53, 54, 54B, 54C and 54D,' thereby bringing transactions covered by section 54D within the capital gains treatment under Section 45, effective from the first day of April, 1974.