Read the dialog and answer the question.

Dewi: Do you know that modern phones don’t need wires to connect to other devices?

Rani: I don’t know. So, how do they work?

Dewi: They use ____ to connect wirelessly to other devices, like headphones and speakers.

Rani: How would you spell that?

Dewi: bi – el – yu – i – ti – ou – ou – ti – eij.

Which correct word can complete the dialog?