What frequency should be used to communicate for runway operations at 4L-22R?

The correct frequency for communicating runway operations at 4L-22R is 126.90 MHz. This frequency is designated specifically for the ground control operations at O'Hare Airport, which is essential for efficient communication between pilots and air traffic control during taxiing and runway access.

Using the correct frequency aids in maintaining safety and coordination among different aircraft and various ground operations at such a busy airport. The other frequencies provided may serve different purposes, such as approach and departure control, but they are not appropriate for the specific runway operations you're inquiring about. Hence, selecting 126.90 MHz ensures that communications remain clear and relevant to your operational needs on the runway.