Answers resolve yes when the individual in question takes on an official role in the new Trump administration before the end of his first hundred days. Roles do not need to be Senate-confirmed (Chief of Staff or Press Secretary counts), but roles that require Senate confirmation must actually be confirmed before they resolve.
NOTE, 11/7 9:44am: An "official role" must include being a formal employee of the United States government. "X is going to be my advisor on confronting the rhinoceros threat" does not count. "X is going to be Assistant to the Deputy Assistant Undersecretary of Agriculture but I am directing everyone in the Executive Branch to obey his instructions on all topics relating to rhinoceroses" does count.
@JeffBerman Czar is typically the nickname for someone who has an official post, so in that case yes. (for instance, the director of the Office of National Drug Control Policy is often called the Drug Czar)
@JeffBerman Follow up: a friend who knows more about the actual functioning, the federal government than I do informs me that occasionally a czar actually has no official position, but by appointing them the president essentially tells everyone in the executive branch that they have to listen to this person on that topic. I would NOT consider that a “yes” — in order to qualify for this market, the individual in question must have a specific official role within the US government.