Answer:
Among the options given on the question the correct answer is option C.
An executive order.
Explanation: The orders which are given by the president of US based on the support of Constitution are called as the executive orders. Executive order manages the federal government and enforce the law. An executive order remain for a uncertain period of time until it proved unlawful or revoked.
The President is given the authority by the Article two of the United States Constitution to execute and enforce to use the discretion to fix how to enforce the law or how to manage the resources or stuffs of the executive brunch. Executive orders have the effect on the government and other departments on how to enforce the law,how to deal with emergencies, waging war etc.
As the head of the state and commander in chief of arm forces, the constitution gives the power to the President to executive order. But the order must need to be on the basis of the constitution.