Which of the following decisions can only be taken by the members in general meeting?

The decision to alter the articles of association can only be made by the members during a general meeting because it involves fundamental changes to the governing rules of the company. The articles of association outline the rights and responsibilities of the members, the management structure, and the procedures for conducting business. Any changes to these articles typically require a special resolution, which must be passed by a significant majority of the members during a general meeting, ensuring that all members have a say in these pivotal decisions.

In contrast, while changing a company's name and reducing capital also involve important changes, these can sometimes be executed without a full general meeting under specific legal provisions or are often handled with less stringent requirements. Appointment of a managing director can typically be made by the board of directors or through resolutions outside of a formal general meeting, depending on the company's articles. Therefore, the alteration of articles is a decision that distinctly requires member approval in a general meeting context.