It conceptually never admits ignorance and never asks for clarifications. It always produces something, to the best of its ability. It _seems_ to be a minor technical limitation (there is plenty of traditional ML systems producing confidence %% alongside the answer from years if not decades ago, in image recognition in particular), but most likely it's actually a very hard problem, as otherwise it would be mitigated somehow by now by OpenAI, given that they clearly agree that this is a serious problem [2] (more generally formulated as reliability [1])

[1] https://www.youtube.com/watch?v=GI4Tpi48DlA&t=1342s (22:22, "Highlights of the Fireside Chat with Ilya Sutskever & Jensen Huang: AI Today & Vision of the Future", recorded March 2023, published May 16, 2023)

[2] https://www.youtube.com/watch?v=GI4Tpi48DlA&t=1400s (23:20, ditto)