Which of the following is a non-legislative power of Congress?

The ability to conduct investigations is a non-legislative power of Congress. This power allows Congress to perform oversight over the executive branch and other areas of government, which is crucial for ensuring accountability and transparency. Congressional committees often investigate various issues, gather information, and hold hearings to examine allegations of wrongdoing or to assess the effectiveness of existing laws and policies. This investigatory function is integral to Congress's role in the balance of powers, as it enables Congress to respond to the needs of the public and ensure the government is functioning appropriately.

In contrast, making laws on taxation, drafting new legislation, and setting national standards are all powers that fall under Congress's legislative authority. Taxation is fundamentally a legislative function as it involves creating laws that govern fiscal matters. Likewise, drafting new legislation directly pertains to Congress's role as the law-making body of the federal government. Setting national standards also relates to legislating because it requires the establishment of legal frameworks that can dictate policies across states or jurisdictions. Each of these tasks involves the creation and formal approval of laws, distinguishing them from the non-legislative power of conducting investigations.