Which of the Following Arguments Commits the Fallacy of Appeal

Which of the following arguments commits the fallacy of appeal to authority?

A) High cholesterol must be bad for you because the surgeon general says so.
B) Hosting a talk show must be hard work because Jay Leno says so.
C) It's harder to get your first record contract than your second because Lady Gaga says so.
D) The Aztec civilization helped to shape the culture of modern Mexico because a leading historian at Yale says so.
E) Yogurt is healthier than ice cream because Arnold Schwarzenegger says so.