I actually own all of these songs since I love to collect music by lists.
"Careless Whisper" was the number one song in the US for 1985 not the UK where is was the number five song. In the US it was Wham! featuring Gorge Michael. From the Wikipedia article...
The song also topped the charts in 25 other countries, including the Billboard Hot 100 in the United States in February 1985 under the credit "Wham! featuring George Michael". Spending three weeks at the top in America, the song was later named Billboard's number-one song of 1985.
Every other song on the quiz that has a featured artist only the credited artist is acceptable much less listed. Please correct.