What power allows the president to block legislation from becoming law?

The ability to block legislation from becoming law is known as the veto power. When Congress passes a bill, it is sent to the president for approval. The president can choose to sign the bill into law or exercise the veto, which prevents the legislation from taking effect. This power serves as a significant check on legislative authority, allowing the president to reject bills that they may consider undesirable or that do not align with their policy objectives. A veto can be overridden by a two-thirds majority in both chambers of Congress, which ensures a balance between the executive and legislative branches.

In contrast, the other options involve different presidential powers. A pardon allows the president to forgive individuals for federal crimes, an executive order is a directive issued by the president to manage operations within the federal government, and appointment refers to the president's power to nominate individuals to various positions in the federal government, such as judges and cabinet members. These powers do not pertain to the process of blocking legislation specifically.