Want a beer?

Three expert logicians - Expert A, Expert B and Expert C - walk into a bar. The bartender asks if all three would like a beer. All three of them answer one after another. The following statements do not necessarily follow the order in which they answered the bartender:

Expert A said "I don't know".

Expert B said "Yes".

Expert C said "I don't know".

Assume that: The logicians do not change their minds after answering. Each logician does not know if the other logicians would like a beer when the bartender asks them. The logicians answer the bartender without communicating amongst themselves who wants a beer.

Which of the following statements is always true?