The answer is: D
Explanation
The correct option is D: Prescribing age bar on enrolment of advocates.
The reason is that the Indian Council of Legal Aid and Advise v. BCI case was about the validity of a rule made by the Bar Council of India (BCI) that barred persons who had completed the age of 45 years from being enrolled as advocates. The Supreme Court held that this rule was ultra vires the Advocates Act, 1961 and violated Article 14 of the Constitution, which guarantees equality before the law and equal protection of the laws. The court also held that the BCI had no authority to prescribe qualifications or disqualifications for membership of a State Bar Council, which was the function of the State Bar Councils under Section 28 of the Act. The court directed the BCI and the State Bar Councils not to implement the said rule.
The other options are incorrect because they are not related to the issue involved in this case. Prescribing pre-enrolment training for advocates, prescribing minimum qualification for an advocate, and prescribing uniform attire for the advocates appearing in the court of law are all matters that fall within the rule-making power of the BCI under Section 49 of the Act, subject to the provisions of the Act and the approval of the Central Government.