What is the phraseology used for canceling a takeoff clearance?

The phraseology "Cancel takeoff clearance (reason)" is the correct choice because it provides clear and unambiguous communication between the pilot and air traffic control (ATC). This phrase ensures that the pilot is adequately instructed to disregard the previously issued clearance to take off, while also allowing the pilot to state the reason for this action if necessary. This helps in maintaining safety and situational awareness for both the pilot and ATC.

Using this phraseology aligns with standard aviation communication practices, where clarity and precision are paramount to avoid misunderstandings that could lead to safety incidents. In addition, providing a reason for the cancellation can assist ATC in understanding the situation and allowing them to provide further guidance or instructions in a timely manner.

Other phrases, while they may convey a similar intention, do not adhere to the established phraseology used in aviation communication. "Cancel departure clearance," for example, pertains more to canceling a clearance for departure from a traffic pattern rather than specifically addressing takeoff. "Abort takeoff clearance" and "withdraw takeoff approval" lack the standardization and clarity required in aviation communications, which is critical in ensuring successful operations in the terminal environment.