How should the clearance be phrased when releasing aircraft N123 two minutes after N65K?

The correct phrasing is “N123 released two minutes after N65K” because it clearly communicates the timing of the release in relation to the other aircraft, N65K. It specifies that N123 is being released at a defined interval after N65K, which is crucial information for maintaining safe separation and situational awareness for both pilots and air traffic control.

Using "after" effectively indicates a chronological order, allowing everyone involved to understand that N123’s clearance comes subsequent to N65K's. This specific terminology helps prevent confusion and ensures that all parties recognize the intended temporal sequence.

The other options may lack clarity or use less standard language, which can lead to misunderstandings. For instance, using “behind” or “post” may not convey the same level of clarity regarding the timing of the release compared to the straightforward use of "after."