Best-of-judgment assessment permitted when returns or notices are not complied with, subject to a show-cause hearing. Section eight is amended to replace 'Income-tax Officer' with Assessing Officer and to add a provision enabling the Assessing Officer, where an assessee fails to make a return or to comply with a statutory notice, to assess the total chargeable interest to the best of his judgment after considering all relevant material and after giving the assessee an opportunity of being heard by serving a show-cause notice specifying date and time; the opportunity need not be given if an earlier notice has already been issued.